Chicago ? Two Chicago men who were schoolmates in Pakistan plotted terrorist attacks against a Danish newspaper that triggered widespread protests by printing cartoons depicting the Prophet Muhammad, federal prosecutors said Tuesday in announcing charges against the men.

David Coleman Headley, 49, traveled to Denmark in January and July to conduct surveillance on possible targets, including the Copenhagen and Aarhus offices of the Jyllands-Posten newspaper, prosecutors said in criminal complaints filed in U.S. District Court in Chicago. Tahawwur Hussain Rana, 48, helped arrange Headley’s travel, prosecutors said.

Danish authorities said there could be more arrests.

According to U.S. prosecutors, Headley visited the newspaper’s Copenhagen offices in January and told employees he represented Rana’s business, First World Immigration Services, and that the business was considering opening offices in Denmark and might buy advertising.

While in Denmark, Headley asked Rana to watch for a follow-up e-mail from an advertising representative from the paper and to ask First World’s Toronto and New York offices to “remember” him in case the newspaper called, prosecutors said. They said Rana corresponded with a newspaper representative and posed as Headley.

Prosecutors said Headley told FBI agents after his Oct. 3 arrest at Chicago’s O’Hare International Airport that the initial plan called for attacks on the newspaper’s offices, but that he later proposed just killing the paper’s former cultural editor and the cartoonist behind the drawings, which triggered outrage throughout the Muslim world. He described his plans to contacts in Pakistan as “the Mickey Mouse project,” according to the FBI.

The newspaper published 12 cartoons depicting the Prophet Muhammad in 2005. One cartoon showed Muhammad wearing a bomb-shaped turban. Any depiction of the prophet, even a favorable one, is forbidden by Islamic law as likely to lead to idolatry.

Headley, a U.S. citizen who changed his name from Daood Gilani in 2006, is charged with conspiracy to commit terrorist acts involving murder and maiming outside the United States. He could be sentenced to life in prison if convicted. He was arrested as he boarded a flight to Philadelphia, the first leg of a trip to Pakistan.

Headley and Rana are each charged with conspiracy to provide material support to a foreign terrorism conspiracy, which carries a maximum sentence of 15 years in prison. Rana, a Canadian citizen, was arrested Oct. 18 in his home.

Headley’s attorney, John Theis, said he would have no comment. Rana’s attorney, Patrick Blegen, said that his client “is a well respected businessman in the Chicagoland community.”