By Lamine Chikhi

ALGIERS (Reuters) - Islamist militants attacked a gas field in Algeria on Wednesday, claiming to have kidnapped up to 41 foreigners including seven Americans in a dawn raid in retaliation for France's intervention in Mali, according to regional media reports.

The raiders were also reported to have killed three people, including a Briton and a French national.

An al Qaeda affiliated group said the raid had been carried out because of Algeria's decision to allow France to use its air space for attacks against Islamists in Mali, where French forces have been in action against al Qaeda-linked militants since last week.

The attack in southern Algeria also raised fears that the French action in Mali could prompt further Islamist revenge attacks on Western targets in Africa, where al Qaeda in the Islamic Maghreb (AQIM) operates across borders in the Sahara desert, and in Europe.

AQIM said it had carried out Wednesday's raid on the In Amenas gas facility in Algeria, Mauritania's ANI news agency reported.

The Algerian interior ministry said: "A terrorist group, heavily armed and using three vehicles, launched an attack this Wednesday at 5 a.m. against a Sonatrach base in Tigantourine, near In Amenas, about 100 km (60 miles) from the Algerian and Libyan border."

The gas field is operated by a joint venture including BP, Norwegian oil firm Statoil and Algerian state company Sonatrach.

BP said armed men were still occupying facilities at the gas field.

"The site was attacked and occupied by a group of unidentified armed people at about 0500 UK time. Contact with the site is extremely difficult, but we understand that armed individuals are still occupying the In Amenas operations site," it said.

Algeria's official APS news agency said a Briton and an Algerian security guard had been killed and seven people were injured including two foreigners. A French national was also killed in the attack, a local source said.

Also among those reported kidnapped by various sources were five Japanese nationals working for the Japanese engineering firm JGC Corp, a French national, an Irishman, a Norwegian and a number of Britons.

(Reporting by Lamine Chikhi in Algiers, additional reporting by Catherine Bremer in Paris; Editing by Angus MacSwan and Giles Elgood)