(CNN) -- A former Libyan military officer who fought against ex-leader Moammar Gadhafi's troops last year was picked to head the country's armed forces, a move that comes as tensions flare among rival militias.
The interim National Transitional Council chose Youssef Mangoush to be chief of staff of the country's armed forces Tuesday.
Mangoush was a member of Libya's special forces and had been retired for years. He worked as a field commander in the battles against Gadhafi's battalions in February. He was arrested in al-Brega in April by Gadhafi forces.
Born in Benghazi in 1950, he enrolled in military school in 1970 and specialized in anti-armor weaponry. He worked in different locations in Libya and fought in Libya's war in Chad, which ended in the 1980s.
Mangoush was also a lecturer and instructor in Libya's military school.
Dirk Vandewalle, an associate professor of government and an expert on Libya at Dartmouth College, said he believes the government was looking for a top military figure who can "straddle difficulties" and 'bridge the gap" between different groups.
"My hunch is this is a compromise more than anyone else," he said.
Four people died in clashes Tuesday in Libya's capital between militias from Tripoli and Misrata, officials said.
The clashes were over control of a building that previously housed an intelligence center under Gadhafi, said Col. Abdul Monem al-Tunsi, a spokesman for the Interior Ministry.
However, former rebels in Tripoli provided different, and conflicting, accounts of what caused the fighting -- meaning the motivations behind it remain unclear.
David Schenker, director of the Program on Arab Politics at the Washington Institute for Near East Policy, noted reports that Mangoush has ties to Misrata. Militias have a strong presence in Misrata, where fighting raged during last year's war between Gadhafi forces and rebels.
He said Mangoush's appointment "suggests or confirms just how bad and how dire the critical situation is regarding the militias."
He said the government isn't making headway on disarming militias and it is covering bases geographically to win over the loyalties of militia members and inspire confidence in the central government.
"His selection is reflective of the government's attempt to improve the situation, to encourage a process of disarmament," he said about Mangoush.
Eric Wiebelhaus-Brahm, a lecturer in international affairs and political science at Florida State University, sees the choice as "partially an attempt to reduce fighting between militias." He says it's "significant" that he has links to Misrata.
"One could read that as being a sign to appease some of the militias that are from the area," Wiebelhaus-Brahm said. "There is probably a calculation going on that he might be better able to bring some militias into the fold of a national army and reduce the factional fighting going on right now."
It's not the first time rival militias have clashed since the war ended, a possible reflection of mutual distrust that could pose a challenge to the nation's new leadership.
In November, dozens of fighters clashed at a Tripoli hospital in what residents said was the biggest armed confrontation in the city since the country was declared liberated. While there were no deaths from gunshots, medical staff said three patients at the hospital died of stress-related causes linked to the fighting.
In December, government officials met to discuss the infighting.
Residents of many Libyan cities, especially Tripoli, are increasingly frustrated, with their streets awash with weapons and armed men who do not answer to a central command. Former fighters complained to CNN about a lack of jobs and support from the National Transitional Council.
Interim government officials have said they will help freedom fighters and incorporate them into the security forces.
CNN's Jomana Karadsheh and Yousuf Basil contributed to this report.