Dozens of people have reportedly been killed in violence between communities in southern Libya over the past several days, underscoring the country’s volatility since the downfall last year of its longtime autocratic leader, Moammar Gaddafi.

Official news media reported late Wednesday that more than 50 people had been killed and 150 injured in clashes between rival armed groups in the main southern city of Sabha, which lies 105 miles from Libya’s Murzuk oil fields.

By Thursday, officials and a witness said, calm had been restored, with the central government in Tripoli dispatching nearly 3,000 troops by land and air to reestablish order. A meeting of tribal elders had also helped to restore calm.

“Now the situation is quiet,” said Fadi Esmali, a freelance journalist in Sabha who was reached by telephone. “I can hear the air force planes overhead bringing in more soldiers.”

The causes of the clashes, which pitted Arabs against Tabu tribesmen, remained murky. Some reports cited a dispute over a motor vehicle that had gone out of control. But Esmali said the violence had deeper roots in tensions between the two communities.

The Tabu, with ties to neighboring Chad, had threatened to break away from Libya over perceived discrimination by the country’s new leaders.

“If the need arises, we will demand international intervention and seek to establish a state, like South Sudan,” Issa Abdul Majid Mansour, leader of the Tabu Salvation Front, declared on Wednesday, according to the English-language Libya Herald.

The Tabu tribesmen were subject to forced evictions and travel restrictions under Gaddafi. But many Libyans who supported the 2011 revolutionary war say they suspect them of having supported the former government. Gaddafi imported hundreds of mercenaries from sub-Saharan Africa during his failed efforts to quell the uprising.

Esmali said, however, that the latest tensions had arisen over how $4 million recently allocated by the interim Transitional National Council would be distributed among various constituencies in Sabha.

“They fight for money, not for any other reason,” he said.

Many observers say they worry that tensions could flare up again. Both sides in the fight are holding captives.

— Financial Times