Libyan rebels sought to stamp out rumours by providing details on the assassination of army chief General Abdel Fatah Yunis while tightening security in their eastern stronghold of Benghazi.

National Transitional Council Chairman Mustafa Abdel Jalil said on Saturday that Yunis had been summoned from the front by a committee of four judges with the knowledge of the NTC's executive committee, the rebels' de facto government.

"The recall of General Fatah Yunis from Ajdabiya was based on a warrant that was issued with the knowledge of the executive committee" of the NTC, he told reporters.

"I don't know why this arrest (warrant) was issued and we don't know who was present at the meeting when the decision was made... or on what basis the decision was made," he added.

Jalil last Thursday announced that Yunis had been killed by an armed group after being summoned to answer questions over military matters.

Yunis was a linchpin of Colonel Moamer Kadhafi's regime before defecting to rebels fighting to oust the strongman since February.

Benghazi has since become a whirlpool of rumours and reports on the motives behind the general's assassination and on the identity of those responsible for his arrest.

Jalil said Yunis died from shots fired at the chest and head and that his body had been only partially burned enabling his positive identification.

He ordered all brigades -- or katibas -- operating in the city of Benghazi to disband and come under the fold of the interior ministry to boost security and unity in the rebel stronghold.

Military spokesman Colonel Ahmed Omar Bani said that the judges who summoned Yunis for questioning did not have the authority do so and that the minister of defence had written a letter recalling the arrest warrant.

He refused to identify suspects arrested in connection with the assassination on the basis that they are innocent until proven guilty.

"When the full truth is known it will be put to the people and the whole world," he said, adding that in the meantime he "will cut the road to those trying to start up rumours among the revolutionaries."

Mahmud Shammam, who handles media for the rebels, slammed foreign and local journalists over their coverage of the general's assassination, saying that "irresponsible news" was being published.

Bani said there was a security breach in Benghazi on Thursday in reference to a prison break for which he blamed members of a "fifth column", zealous defenders and informants of Kadhafi's regime. Some of the escapees remain at large.

In Zuwaytina, the Union of Revolutionary Forces late Saturday dismissed reports that Yunis was a traitor killed by his own people for providing strategic military information to Kadhafi's regime.

"Anybody can say anything but all this big talk needs proof. The chief of staff was always with us from the beginning," said Fawzi Bukatif, spokesman of the Union of Revolutionary Forces and head of the February 17 brigade.

The Union of Revolutionary Forces, which was formed on July 13, provides a unified command structure for fighters from volunteer brigades, who now fall under the authority of the rebels' ministry of defence.

He condemned the general's assassination as a "cowardly act" and said that Yunis's arrest and assassination took place without the knowledge nor consent of the Union of Revolutionary Forces.

"We have no relation with the arrest of Yunis or everything that happened... whatever happened was not by our orders," he said, adding that brigades not affiliated with the Union of Revolutionary Forces arrested Yunes.

Bukatif said that the Obeida Ibn al-Jarah brigade, which an NTC member mentioned earlier as a potential culprit, was not part of the rebel body and no longer fighting on the front, which lies near the strategic oil hub Brega.

He added that Mustafa Rubaa -- who belongs to the Union of Revolutionary Forces "as an individual" but not as part of a brigade -- was detained for his role in the arrest of Yunis.

The villa of the assassinated general in Benghazi was surrounded by checkpoints and no traffic was allowed on the coastal city's main highway before dawn Sunday as AFP received unconfirmed reports of clashes.

South of Benghazi, rebels reported an attack by pro-Kadhafi forces on the southern oasis town of Jalo but said that it had been successfully repelled.

Kadhafi's regime meanwhile accused NATO of killing three journalists in an air strike on state television on Saturday and said that the murder of the rebels' army chief proved Al-Qaeda was instigating the country's armed revolt.

Deputy foreign minister Khaled Kaaim said early Sunday the Kadhafi regime was in contact with members of the NTC.

"There are contacts with Mahmud Jibril (number two in the NTC), and (Ali) Essawy (in charge of external relations), (religious leader Ali) Sallabi and others," Kaaim told a news conference in the capital.

The deputy minister denied rumours about recent contacts between the regime and Yunis.

Meanwhile diplomats said that the UN Security Council is ready to release Libyan assets frozen under UN sanctions to buy humanitarian aid for the population facing growing shortages.