NAPLES, Jan 31: Italian authorities arrested 28 Pakistanis in Naples earlier this week after finding maps and explosives in their apartment, and have charged them with terrorist offences, a judicial source said on Friday.

The men, most of whom are believed to be illegal immigrants, were arrested during a routine sweep on Wednesday night. Police found explosives, fuses, maps and other documents in their apartment, the source told Reuters.

Some of the documents, said to be written in an Arabic script, have been taken for translation.

The public prosecutor has charged the men with conspiracy and association with international terrorism.

Italy’s ANSA news agency, citing no sources, said: “Huge amounts of explosives and detailed maps of Naples, with several areas marked, had been seized by the police.” Naples, a port city, is the headquarters of Nato’s southern European command.

In nearly 18 months since the Sept 11 attack on the United States, more than 110 people have been arrested in Italy on suspicion of links to terror organizations. While a few have been convicted, most have been released for lack of evidence.

Police have grown increasingly wary of announcing what appear to be breakthroughs in the fight against terrorism, and sources said magistrates were irritated on Friday that news of the latest arrests had got out.

Newspapers reported details of an 18-month investigation by Italian anti-terrorism police, with the help of the CIA, into a possible “sleeping cell” of militants belonging to Al Qaeda.

The newspaper La Repubblica said the probe had generated hundreds of pages of documents, and links had been found between the cell in Turin and militants in Afghanistan and Chechnya, but not enough evidence had yet been gathered to make arrests.

German media said last week that German intelligence had warned of 20 Afghan “terror commandos” travelling on false Pakistani passports to Germany, Britain, France and the Czech Republic.

Also last week, Spainish authorities arrested 16 suspected extremists linked to Al Qaeda who were allegedly preparing to launch chemical attacks.