Benghazi, Libya: A doctor at the main hospital in the southern Libyan city of Sabha says at least 20 people have been killed in tribal clashes there.

Surgeon Ahmad Ali Al Hefnawi says most of the fighters died from gunshot wounds.

The deadly clash underlined the fragile nature of Libya after the fall of longtime leader Muammar Gaddafi. The central government has failed to impose its authority, and Libya is ruled instead by squabbling tribes and militias.

The latest clashes erupted after a man from the Tabu tribe allegedly killed a member of the Abu Saif tribe.

According to Hassan Mousa, a commander of the Tabu tribe in Sabha, his people were supposed to meet the Abu Saif tribe for reconciliation when they came under attack Monday.

Government officials said they are investigating.