BP has privately questioned how the plant came to be attacked. Sources have noted that it was located in a militarised zone supposedly protected by 3,000 Algerian troops.
The Algerian army is under pressure to explain how 40 insurgents, heavily armed with rocket launchers, were able to cross the border through Libya and take the plant by surprise. People who have worked at the site, which sits with its back to cliffs in the dunes, say there was normally an overnight curfew on movement in the area, leaving it unclear how the gunmen were able to get so close before being challenged.