Libyan jihadist group Ansar al-Sharia denied on Tuesday that the Al-Qaeda-linked mastermind of a deadly 2013 siege at an Algerian gas plant had been killed in a US air strike.

The group named seven people it said were killed in the US strike in eastern Libya but Mokhtar Belmokhtar, who Washington has said was the target, was not among them.

"No other person was killed," the group said in a statement.