BANGKOK — The chief editor of a prominent Indonesian newspaper, the English-language Jakarta Post, has been summoned for questioning by the police for publishing a cartoon that depicted radical Islamists in Syria.

The editor, Meidyatama Suryodiningrat, is being treated as a suspect under a blasphemy law, according to a police spokesman quoted in the Indonesian news media on Friday.

The cartoon, which ran in the daily newspaper in July, shows militants raising a black flag emblazoned with a skull and crossbones and Arabic phrases, including, “There is none worthy of worship except Allah.” In the background was a white pickup truck and what appeared to be the imminent execution of a row of blindfolded people on their knees.

It was drawn by Stephane Peray, a French cartoonist based in Bangkok who syndicates his work. “Don’t want to talk about it,” Mr. Peray said by email.