BENGHAZI, Libya - Mourners brought a coffin carrying the body of Libyan rebel military commander Abdel Fatah Younes into the main square of Benghazi on Friday, his nephew said.

"We got the body yesterday (on Thursday) here (in Benghazi), he had been shot with bullets and burned," Younes' nephew, Abdul Hakim, said as he followed the coffin through the square of the main rebel-held town.

Younes was killed in mysterious circumstances on Thursday after being recalled to Benghazi from the front line near the oil port of Brega.

Younes was shot dead by an armed gang after he was summoned from the front by the rebel National Transitional Council (NTC) "for questioning over military issues", NTC chairman Mustafa Abdel Jalil said late on Thursday.

His killing, and that of two military officers, is seen as a sign of divisions within the ranks of the rebels in eastern Libya even as they make fresh advances in the west in a pre-Ramadan push to drive out leader Muammar Gadhafi.

"With all sadness, I inform you of the passing of Abdel Fatah Younes, the commander-in-chief of our rebel forces," Abdel Jalil said in a carefully worded statement at a news conference in Benghazi, the rebels' eastern capital.

"The person who carried out the assassination was captured," Abdel Jalil said without elaborating. He added there would be three days of mourning in Younes' honor.

Rumors circulated in Benghazi that Younes, Libya's former interior minister and No 2 in Gadhafi's government prior to his defection in February, was arrested and killed by the rebels themselves after it was alleged his family still had ties with Gadhafi but these could not be confirmed by AFP.

The scenario that the rebels have started fighting among themselves could pose awkward problems for the many Western powers who have recognized the NTC as the sole legitimate authority in Libya.

Rebel leaders tried to dampen down the speculation.

Moments after the announcement, two vehicles loaded with an anti-aircraft gun and at least a dozen armed men shooting in the air arrived at Tibesti hotel, where the announcement was made.

A witness said that they later managed to enter the hotel with their weapons but security forces calmed them down and convinced them to leave.

"They shouted 'You killed (Younes)'," in reference to the NTC, he added.

At least three loud explosions shook the center of Tripoli late on Thursday, as Libyan television reported that planes were flying over the Libyan capital, which has been the target of NATO air raids.

Al-Jamahiriya television reported that several "civilian sites" had been bombed by NATO on Thursday.