An Islamist militia allied to Libya's rebel opposition is behind the death of their military commander Abdel Fattah Younes, a National Transitional Council minister has said.

Ali Tarhouni, who is the finance and oil minister for the NTC, recently recognised by several countries including Britain as the legitimate Libyan authority, said Younes was killed by a group known as the Obaida Ibn Jarrah Brigade.

General Younes defected to the rebels in February after the beginning of the Libyan uprising. He had served under Gaddfi since the revolution of 1969.

Younes body was found shot and burned with those of two of his aides on Friday.

"His lieutenants did it," said Tarhouni, according to the Reuters news agency.

If true, the revelation will cast fresh doubt on the rebels' ability to fight as a group and form a stable government.

It will also be troubling for British Foreign Secretary William Hague and others who have publicly put their faith in the rebels.

Hague announced on Wednesday that Britain would recognise the NTC as the representative government of Libya after similar announcements by the US and French governments.

The decision was mocked by Colonel Muammar Gaddafi's spokesman Moussa Ibrahim, who said that the slaying of Younes was "a slap in the face" to the British government.

"By this act, al-Qaeda wanted to mark out its presence and its influence in this region."

"The other members of the National Transitional Council knew about it but could not react because they are terrified of al-Qaeda."

Meanwhile Nata warplanes carried out a series of strikes on Libyan state television satellite transmitters in Tripoli, in an attempt to silence internal government messages that the alliance says are threatening civilians and inciting violence.

"Striking specifically these critical satellite dishes will reduce the regime's ability to oppress civilians while (preserving) television broadcast infrastructure that will be needed after the conflict," Nato said in a statement.

According to reports, however, Libyan state television was broadcasting as normal as of Saturday morning.