CAIRO -- Saturday's United Nations mission to Libya expressed concern over clashes at Tripoli. This was after a night of intense fire between militias in Tripoli.

The latest fighting is taking place in Libya, which is now divided between two competing governments. One of these is based at Tripoli, despite having taken more than a decade of tentative steps towards unification.

The mission stated that the clashes were threatening civilians and urged Libyans to do all they could to protect the fragile stability of the country at this delicate time.

Although the cause of violence in the seaside area was not clear, videos posted on social media showed children's families fleeing artillery fire as they fled to safety. Two of the city's powerful militias were accused of infighting.

For years, Libya was divided between rival administrations in the east or west. Each is supported by different well-armed militias or foreign governments. Since the NATO-backed 2011 uprising that toppled long-time dictator Moammar Gadhafi, the Mediterranean nation has been in turmoil.

After the failure of elections last year, an interim government based in Tripoli led by Prime Minister Abdul Hamid Dbeibah fell short of its plan for a transition to an elected government, the country's plan was abandoned.

Dbeibah has not resigned since then, raising doubts about his mandate. The country's East-based lawmakers elected Fathy Bashagha as a rival prime Minister. This powerful former interior minister is currently running a separate administration from Sirte.

Dbeibah called a powerful commander of the 444 brigade, which serves his government, to urge him to do all he can to restore peace to Tripoli.

Bashagha was his rival and he called for armies to surrender in a series tweets. Bashagha, who attempted to establish his government in Tripoli last month, fled within hours of fighting that claimed the lives of one person.