Clashes between rival militia factions have rocked Tripoli, shattering months of relative calm in the Libyan capital. 

The violence broke out overnight and continued into Tuesday morning. It took place in different parts of Tripoli, residents and local media reported. It appears to be the worst flare-up of fighting in the city this year.

The exact death toll from the clashes remains unclear, but one estimate said 27 people were killed and another 100 were wounded in the fighting.

What is the latest?

A medical unit linked to the Defense Ministry said it had recovered three bodies from the Furnaj, Ain Zara and Tarik Shok districts.

Ambulance services spokesperson Usama Ali said 19 people had been injured and 26 families evacuated from a district hit by fighting.

The Health Ministry said many of Tripoli's residents have been trapped in their homes.

In a statement, it called on the warring parties to allow ambulance and emergency teams to enter the affected areas and for blood to be sent to nearby hospitals.

The clashes seemed to have calmed later on Tuesday after the Special Deterrence Force released 444 Brigade commander Mahmoud Hamza.

Reuters news agency cited unnamed sources from each of the factions as saying that Hamza was handed over to a third group that was not involved in the fighting.

What triggered the violence?

According to local media, fighting broke out between the 444 brigade and the Special Deterrence Force late Monday evening.

The groups are viewed as the Libyan capital's most powerful armed factions.

The 444 brigade is backed by the Interior Ministry in Tripoli. The Special Deterrence Force controls the capital's Mitiga airport.

Tensions flared on Monday after the Special Deterrence Force allegedly detained 444 Brigade commander Mahmoud Hamza as he attempted to travel, media reported.

Dark smoke hung over parts of the city early on Tuesday, and the sound of heavy weapons rattled through the streets, a Reuters journalist said.

Flights to and from Mitiga airport have been diverted due to the fighting. The University of Tripoli has canceled classes.

A divided nation

Libya, an oil-rich nation located in the Maghreb region of northern Africa, has been in turmoil since the overthrow of dictator Moammar Gadhafi in 2011.

The country has been split into two since 2014, with opposing governments located in the eastern and western parts of the nation, respectively.

A United Nations-backed administration known as the Government of National Unity is based in Tripoli in the west, and its rival, known as the House of Representatives, is based in the east, in Tobruk.

Each is supported by a number of local militias and foreign powers, and each has tried to wrest control from the other.

However, after several years of fighting and instability, the violence has largely subsided. 

Still, in Tripoli, longstanding divisions have sparked several incidents of bloodshed in recent years.

The United Nations Support Mission in Libya released a statement on Tuesday saying it was following with concern "the security incidents and developments" that began Monday.

It called for an immediate end to the ongoing armed clashes.

sri/wd (AP, Reuters, dpa)