Six foreign hostages and eight of their captors were killed when Algerian forces fired on a vehicle being used by besieged gunmen at a gas plant in the remote Algerian desert yesterday, a local source said. Mauritania's ANI news agency, which has been in constant contact with the kidnappers, said seven hostages were still being held: two Americans, three Belgians, one Japanese and one British citizen. The stand-off, which began when gunmen stormed the gas plant yesterday morning demanding a halt to a French military operation in neighbouring Mali, has unfolded into one of the biggest international hostage crises in decades. An Algerian security source said 25 foreign hostages had escaped alive. The local source in the town who gave the death toll in the strike said 180 Algerian hostages had also managed to flee. Britain and Norway, whose oil firms BP and Statoil run the plant jointly with the Algerian state oil company, said they had been informed by the Algerian authorities that a military operation was under way. ANI and the Qatar-based Al Jazeera reported that 34 of the captives and 15 of there captors were killed when government forces fired from helicopters at a vehicle. However, those death tolls were far higher than confirmed by the local source and also contradict the reports that large numbers of foreigners escaped alive. A group calling itself the Battalion of Blood said it initially seized 41 foreigners, including Americans, Japanese and Europeans, after storming the gas pumping station. The attackers have demanded an end to the French military campaign in Mali, where hundreds of French paratroopers and marines are launching a ground offensive against rebels a week after French aircraft began firing on militants from the air.