In Libya, a shopkeeper's monkey pulled off a Muslim girl's head scarf. This ignited a dispute between two already warring tribes, one of whom is Muslim.
"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.
At least 21 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 toppled dictator Moamer Gadhafi's 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.