ROME – Italian police arrested three Moroccans — an imam and two of his aids — they accuse of being part of a militant cell that allegedly used a mosque in a central Italian city as a terror training camp.

The group held courses on hand-to-hand combat and used propaganda films and documents downloaded from the Internet to teach how to prepare poisons and explosives, pilot a Boeing 747 and send encrypted messages, anti-terrorism police in Rome said in a statement.

A fourth Moroccan was still being sought and was believed to be abroad, police said.

The four, arrested in the city of Perugia, are accused of international terrorism, with the arrests coming after a two-year investigation.

An additional 20 people who frequented Perugia’s Ponte Felcino mosque were placed under investigation for various charges, including violating Italy’s immigration laws, police said.