Tripoli: An umbrella group of former rebels who fought against toppled dictator Muammar Gaddafi on Thursday rejected the appointment of Yussef al-Mangush as chief of staff of the new Libyan army.

"We reject anybody who is not among the list of six candidates proposed by us to the NTC (National Transitional Council)," Behlool Assid, a founder of the Coalition of Libyan Thwars (Revolutionaries), told on the sidelines of a news conference.

He said Mangush was not among the candidates proposed by his group which represents factions of former rebels from major Libyan cities such as Benghazi, Misrata and Zintan.

Assid told reporters that his group was disappointed as NTC chief Mustafa Abdel Jalil himself on December 21 had urged the rebels to put forward names for the chief of the national army.

"The thwars had agreed to support the candidate who is selected from the list we proposed... we feel that the procedure with which Mangush has been appointed is illegal," Assid told reporters, adding that "selecting the army chief is not so easy."

On Wednesday, two NTC members, Abdelrazzak al-Aradi and Fathi Baaja, told that Mangush, a former colonel in Gaddafi's military, had been chosen to head the army.

The post of chief of staff has been vacant since the murder last July of General Abdel Fatah Yunis, who commanded the rebels in eastern Libya against Gaddafi's diehards.

Yunis had been expected to head the new Libyan army when it was formed.

Mangush is currently the deputy defence minister in the interim government of Prime Minister Abdel Rahim al-Kib.

During the conflict, Mangush was arrested in the oil town of Brega in April by Gaddafi's forces and freed in late August following the fall of Tripoli.

Several officers in the former army have criticised the NTC for moving slowly on appointing a new chief of staff, saying the delay had also held back the formation of a new army and the integration of former rebels.

Forming a new army is seen as a key step towards disarming militias in Libya, especially in the capital Tripoli where a firefight between ex-rebels today killed four people.

(Agencies)