Police in Spain's North African enclave of Ceuta have arrested at least 11 suspected Islamic militants.

Police sources say forces sent by boat from the Spanish mainland carried out the sweep in pre-dawn raids early Tuesday across the tiny enclave on Morocco's northwestern coast.

Authorities identified two of the detainees as brothers of Hamed Abderrahaman Ahmed, a Spaniard who spent two years in detention at the U.S. naval base in Guantanamo Bay, Cuba, after his 2001 capture near the Afghan-Pakistani border. Authorities say Ahmed, who was released earlier this year by a Spanish court, was not among those arrested today.

The French news agency, AFP, quotes Spanish anti-terror services as saying authorities were alerted when a group linked to al-Qaida posted a document on the Internet calling for "a war against the infidel Spanish state."

Some information for this report was provided by AFP, AP and Reuters.