BERLIN — The police in seven countries, trying to stanch the mass migration of Kosovars through Serbia and into the European Union, arrested 77 people accused of running a smuggling operation, the European authorities said on Wednesday.

The announcement of the arrests appeared intended not only to deter smugglers but also to signal that European officials are cracking down on the tens of thousands of ethnic Albanians from Kosovo who started streaming north last fall.

Germany, Austria, Switzerland and other countries were shocked by the sudden influx of asylum applications, which are unlikely to be granted. In Austria, up to 550 people a week had been arriving this year, though the flow has trickled to 40 to 50 a week, the Austrian federal criminal office said Wednesday.

Forty-six people were arrested on Tuesday, including eight in Vienna, 16 in the Czech Republic, 12 in France, four in Hungary, three in Kosovo, two in Slovakia and one in Germany, the pan-European Europol and Eurojust offices in The Hague announced.