Benghazi (AsiaNews/Agencies) - Great Britain, Germany, the Netherlands and Australia have urged their citizens to leave the Libyan city of Benghazi due to a "specific, imminent threat to Westerners", linked to French action in Mali and the danger of new kidnappings by Muslim extremists.

According to British diplomatic sources, Islamists have threatened to carry out attacks against Western targets like the one on the US consulate on 11 September 2011 in which US Ambassador to Libya Christopher Stevens and three other Americans were killed.

Over the past two years since the anti-Gaddafi war, Benghazi has been one of the main recruiting centres for Islamic extremists and al-Qaeda fighters.

A senior Algerian officer claimed that the organisers of the Benghazi consulate attack are the same who seized the gas Tigantourine field in (in In Amenas, south-eastern Algeria) that left 38 hostages and 29 Muslim extremists dead.

The group recruited by Mokhtar Belmokhtar included several Egyptian jihadists active in Libya.

Sources in Algiers said that Mohamed-Lamine Bouchneb, the militant leading the attack at the site, had purchased arms for the assault in the Libyan capital, Tripoli.

The kidnappers gathered, undisturbed, at the southern Libyan town of Ghat, just across the border from Algeria, before their attack.

It is becoming clear that al Qaeda is spreading in the Sahara. On Wednesday, US Secretary of State Hillary Clinton spoke to Congress about the events in Benghazi, warning that Jihadist groups have formed a complex alliance in North Africa with southern Libya and Mali as their main bases.

Indeed, Mokhtar Belmokhtar, the veteran militant who claimed overall responsibility for the Tigantourine attack, is believed to be based in Mali.

US State Department officials have said that some members of Ansar al-Shariah, the group that carried out the attack on the diplomatic mission in Benghazi, had connections to al Qaeda in the Islamic Maghreb, one of the militant groups now holding northern Mali.