(CNN) Swiss police have arrested two people with Syrian passports and found traces of potential bomb-making chemicals in a car as security remains high around Geneva amid a terrorism alert and a hunt for suspects, authorities said Saturday.

Authorities have been looking for at least two people with indirect links to suspects in the November 13 Paris terrorist attacks. It was not immediately clear whether Saturday's arrests were linked to the attacks in Paris, in which 130 people were killed

The two were arrested Friday and charged Saturday, according to a statement Saturday from the Office of the Attorney General of Switzerland.

A photo posted by Nic Robertson (@nicrobertsoncnn) on Dec 13, 2015 at 2:39am PST

They were arrested on suspicion of the manufacture, concealment and transport of explosives or toxic gases, as well as on suspicion of violating the prohibition of groups such as al Qaida, ISIS and similar organizations.

Geneva Minister of Economy and Security, Pierre Maudet, told CNN two people of Syrian origin were arrested in the greater Geneva area.

The two suspects had Syrian passports, Geneva prosecutor Olivier Jornot told reporters in Geneva Saturday.

Investigators still have to determine the link between the two suspects and the traces of explosives found in their vehicle, Jornot said. The presence of such evidence does not mean that the two were involved in transporting explosives in the vehicle, and they claimed that they had acquired the vehicle recently, the prosecutor said.

According to a European security source briefed on the investigation, the materials Swiss police found were traces of precursor products. Precursor products are chemicals which could be turned into explosives or other harmful substances.

'From a vague threat to a precise threat'

During a house search, which had no direct connection to the ongoing terror threat in the Geneva area, police discovered Thursday that an individual who was described as a right-wing sympathizer and survivalist had accumulated an "impressive" quantity of weapons, Jornot said.

The arsenal included Kalashnikovs, a M16, two Glock handguns, a MG42 machine gun and one pump-action shotgun, as well as other weapons, described as antique guns, Jornot said. Police also found a Nazi flag, he said.

The alert level in the city remains high, but Swiss authorities said various events planned over the weekend will go on.

The U.S. Embassy warned Americans in Switzerland to "maintain a high level of vigilance."

The Swiss alert came after a tip from U.S. intelligence officials, who told their Swiss counterparts that they had intercepted communications among extremists discussing the idea of attacking Geneva, as well as Chicago and Toronto, a source close to the investigation told CNN.

Authorities were looking for at least two other people with indirect links to suspects in the November 13 Paris terror attacks.

"We have gone from a vague threat to a precise threat," Emmanuelle Lo Verso, head of communications at the Geneva Department of Security, told CNN on Friday. She would not comment further.

Photos: Night of terror: Paris attacks A forensic scientist works near a Paris cafe on Saturday, November 14, following a series of coordinated attacks in Paris the night before that killed scores of people. ISIS has claimed responsibility. Hide Caption 1 of 32 Photos: Night of terror: Paris attacks Police are out in force November 14 near La Belle Equipe, one of the sites of the terror attacks. Hide Caption 2 of 32 Photos: Night of terror: Paris attacks Forensic police search for evidence inside the Comptoir Voltaire cafe after the attacks. Hide Caption 3 of 32 Photos: Night of terror: Paris attacks Shoes and a bloody shirt lie outside the Bataclan concert hall on November 14. Most of the fatalities occurred at the Bataclan in central Paris. Hide Caption 4 of 32 Photos: Night of terror: Paris attacks Security forces evacuate people on Rue Oberkampf near the Bataclan concert hall early on November 14. Hide Caption 5 of 32 Photos: Night of terror: Paris attacks Medics evacuate an injured woman on Boulevard des Filles du Calvaire near the Bataclan early on November 14. Hide Caption 6 of 32 Photos: Night of terror: Paris attacks Police, firefighters and rescue workers secure the area near the Bataclan concert hall on November 14. Hide Caption 7 of 32 Photos: Night of terror: Paris attacks A man with blood on his shirt talks on the phone on November 14. He is next to the Bataclan theater, where gunmen shot concertgoers and held hostages until police raided the building. Hide Caption 8 of 32 Photos: Night of terror: Paris attacks Police officers patrol the area around Notre Dame cathedral in Paris on November 14. Hide Caption 9 of 32 Photos: Night of terror: Paris attacks Police officers patrol Paris' Saint-German neighborhood on November 14. Hide Caption 10 of 32 Photos: Night of terror: Paris attacks Victims of the shooting at the Bataclan concert venue in central Paris are evacuated to receive medical treatment on November 14. Hide Caption 11 of 32 Photos: Night of terror: Paris attacks A woman is evacuated from the Bataclan theater early on November 14. Hide Caption 12 of 32 Photos: Night of terror: Paris attacks Forensics are working in the street of Paris after the terrorist attack on Friday, November 13. The words "horror," "massacre" and "war" peppered the front pages of the country's newspapers, conveying the shell-shocked mood. Hide Caption 13 of 32 Photos: Night of terror: Paris attacks Rescuers evacuate an injured person near the Stade de France, one of several sites of attacks November 13 in Paris. Thousands of fans were watching a soccer match between France and Germany when the attacks occurred. Hide Caption 14 of 32 Photos: Night of terror: Paris attacks A survivor of the terrorist attack in the Bataclan is assisted following terror attacks, November 13. The violence at the Bataclan, which involved a hostage-taking, resulted in the highest number of casualties of all the attacks. Hide Caption 15 of 32 Photos: Night of terror: Paris attacks Spectators invade the pitch of the Stade de France stadium after the international friendly soccer match between France and Germany in Saint-Denis. Hide Caption 16 of 32 Photos: Night of terror: Paris attacks Spectators embrace each other as they stand on the playing field of the Stade de France stadium at the end of a soccer match between France and Germany in Saint-Denis, outside Paris, on November 13. Hide Caption 17 of 32 Photos: Night of terror: Paris attacks A body, covered by a sheet, is seen on the sidewalk outside the Bataclan theater. Hide Caption 18 of 32 Photos: Night of terror: Paris attacks Rescuers evacuate an injured person on Boulevard des Filles du Calvaire, close to the Bataclan concert hall in central Paris. Hide Caption 19 of 32 Photos: Night of terror: Paris attacks Wounded people are evacuated outside the scene of a hostage situation at the Bataclan theater in Paris on November 13. Hide Caption 20 of 32 Photos: Night of terror: Paris attacks A medic tends to a wounded man following the attacks near the Boulevard des Filles du Calvaire. Hide Caption 21 of 32 Photos: Night of terror: Paris attacks A woman walks past police and firefighters in the Oberkampf area of Paris. Hide Caption 22 of 32 Photos: Night of terror: Paris attacks A riot police officer stands by an ambulance near the Bataclan concert hall in central Paris. Hide Caption 23 of 32 Photos: Night of terror: Paris attacks Wounded people are evacuated outside the Bataclan concert hall. Hide Caption 24 of 32 Photos: Night of terror: Paris attacks Police secure the Stade de France in Saint-Denis, north of Paris, following explosions during the soccer match between France and Germany. Hide Caption 25 of 32 Photos: Night of terror: Paris attacks A wounded man is evacuated from the Stade de France in Saint-Denis, outside Paris. Hide Caption 26 of 32 Photos: Night of terror: Paris attacks Spectators gather on the field of the Stade de France after the attacks. Explosions were heard during the soccer match between France and Germany. Hide Caption 27 of 32 Photos: Night of terror: Paris attacks French security forces rush in as people are evacuated in the area of Rue Bichat in the 10th District of Paris. Hide Caption 28 of 32 Photos: Night of terror: Paris attacks People leave the Stade de France after explosions were heard near the stadium during a soccer match between France and Germany on Friday. Paris Deputy Mayor Patrick Klugman told CNN President Francois Hollande was at the match and was evacuated at halftime. Hide Caption 29 of 32 Photos: Night of terror: Paris attacks Victims lay on the pavement outside a Paris restaurant. Hide Caption 30 of 32 Photos: Night of terror: Paris attacks Rescue workers and medics tend to victims at the scene of one of the shootings, a restaurant in the 10th District. Attackers reportedly used AK-47 automatic weapons in separate attacks across Paris, and there were explosions at the Stade de France. Hide Caption 31 of 32 Photos: Night of terror: Paris attacks French security forces move people in the area of Rue Bichat in the 10th District. A witness told BFMTV that firefighters were on the scene to treat the injured. Hide Caption 32 of 32

Police chief: ISIS cell could exist in Geneva

Whatever the nature of that threat, it was likely more well developed than any possible danger for Chicago or Toronto, said CNN national security analyst Juliette Kayyem.

Kayyem said she suspects that "the intelligence about Geneva was stronger, more specific than it was about the other cities because you're simply not hearing about that kind of reaction from either Toronto or Chicago at this stage."

Geneva police Chief Monica Bonfanti told radio broadcaster RTS that there is "the possibility of the presence of an Islamic State [ISIS] terror cell in Geneva."

Bonfanti said police were searching for suspected terrorists, but wouldn't comment on the number of people involved in the hunt.

In Switzerland, authorities raised the terror alert level and deployed more armed police officers on the streets.