In coordinated raids, the Swedish and Norwegian security services on Thursday arrested six people on suspicion of financing or otherwise taking part in terrorist activity.

Spokesmen for the two security services did not identify the suspects, but numerous news reports described them as being of Somali heritage and living in or around Stockholm and Oslo.

The three arrested in Norway were to appear in court Friday or Saturday to face possible charges of “financing terror actions,” said Martin Bernsen, information officer for the Norwegian Police Security Service. He said they are accused of financing activity that took place in Norway , while the terrorism actions in question took place abroad.

The Swedish suspects, whom the authorities said were Swedish citizens, were accused not only of participating in terrorism-related financial activity but also of “preparations for committing terrorist crimes,” said Jakob Larsson, the press director of the Swedish Security Service.

The Swedish suspects were also expected to make court appearances in the near future, at which time more information about the nature of the offenses is likely to become public. In Oslo on Thursday afternoon, police officers and other security officials served search warrants on at least two Internet cafes and were seen carrying out computer equipment.

In recent weeks some Muslim groups in Denmark have been angered after newspapers across the country reprinted caricatures of the Prophet Muhammad. Violent protests raged around the Muslim world in 2005 and 2006 after the Danish newspaper Jyllands-Posten published 11 Muhammad cartoons, including one depicting the prophet with a bomb in his turban. Islamic law is generally interpreted as forbidding any representation of the prophet.

Mr. Larsson, of the Swedish Security Service, dismissed speculation in the news media that the arrests on Thursday were related to threats against a Swedish cartoonist who last summer drew a cartoon of the Prophet Muhammad that was published in a local newspaper.