At least 16 people died and 50 were wounded in Libya in four days of clashes between rival factions in the southern city of Sabha, a health official said on Sunday.

According to residents and local reports, the latest bout of violence erupted between two tribes after an incident in which a monkey that belonged to a shopkeeper from the Gaddadfa tribe attacked a group of schoolgirls who were passing by.

The monkey pulled off one of the girls' head scarf, leading men from the Awlad Suleiman tribe to retaliate by killing three people from the Gaddadfa tribe as well as the monkey, according to a resident who spoke to Reuters.

City officials could not be reached to confirm the accounts.

"There was an escalation on the second and third days with the use of tanks, mortars and other heavy weapons," the resident told Reuters by telephone, speaking on condition of anonymity because of the denigrating security situation.

"There are still sporadic clashes and life is completely shut down in the areas where there has been fighting."

Like other parts of Libya, Sabha has been periodically plagued by conflict since the uprising that toppled Muammar Gaddafi five years ago splintered the country into warring factions.

In the Sabha region, a hub for migrant and arms smuggling in Libya's often neglected south, militia abuses and the deterioration of living conditions have been especially acute.

The Gaddadfa and the Awlad Suleiman represent the most powerful armed factions in the region.

During the latest clashes, which took place in the city center, initial attempts by tribal leaders to calm the fighting and arrange a ceasefire so that bodies could be recovered had failed, residents said.

Fighter of Libyan forces allied with the U.N.-backed government aims his weapon as he takes up position inside a ruined house at the front line of fighting with Islamic State militants in Ghiza Bahriya district in Sirte Thomson Reuters

By Sunday, Sabha Medical Centre had received the bodies of 16 people killed in the clashes and some 50 wounded, said a spokesman for the center.

"There are women and children among the wounded and some foreigners from sub-Saharan African countries among those killed due to indiscriminate shelling," he said.

The city lies about 660km (410 miles) south of Tripoli.