Fighting between the influential 444 Brigade and the Special Deterrence Force has raged this week after months of relative peace.
The worst armed clashes in a year have killed 55 people in Libya’s capital, Tripoli, authorities have said.
The death toll from the fighting was announced on Wednesday by Tripoli’s health authorities, which also said 146 people had been injured.
Major warfare in Libya has been paused since a 2020 truce between the main eastern and western sides.
But rival factions still hold the most territory and a lasting solution to the conflict that has raged since a 2011 NATO-backed uprising looks distant.
Here is what you need to know about the latest unrest:
Who is fighting?
Fighting raged from Monday night into Tuesday between the influential 444 Brigade and the Special Deterrence Force, or al-Radaa Force.
The 444 Brigade is affiliated with Libya’s defence ministry and is reputed to be the North African country’s most disciplined armed group.
The Special Deterrence Force is a powerful ultraconservative militia that acts as the capital’s police force.
They are two of myriad militias vying for power since the 2011 overthrow of longtime dictator Muammar Gaddafi, growing in wealth and power, particularly in Tripoli and the west of the country.
The 444 Brigade and the Special Deterrence Force are among the largest militias in Tripoli and have been backed by the Tripoli-based government in the west of the country, led by Prime Minister Abdul Hamid Dbeibah.
Since 2014, Libya has been divided between rival administrations in the east and the west, each supported by an array of well-armed militias and different foreign governments.
What triggered the fighting?
The clashes with rocket launchers and machine guns followed the detention of the 444 Brigade head, Colonel Mahmoud Hamza, on Monday as he tried to travel from Tripoli’s Mitiga airport, which the Special Deterrence Force controls.
A total of 234 families were evacuated from front-line areas in the capital’s southern suburbs, along with dozens of doctors and paramedics trapped by the fighting while caring for the wounded, the Emergency Medical Centre said.
Late Tuesday, the social council in the southeastern suburb of Souq el-Jumaa, a stronghold of the Special Deterrence Force, announced that an agreement had been reached with Dbeibah for Hamza to be handed over to a “neutral party”.
In a televised announcement, the council said a ceasefire would follow the transfer of the commander and, late on Tuesday, the fighting abated.
Hamza was returned to his unit on Wednesday, officials in the commander’s organisation said.
Anas el-Gomati, director of the Sadeq Institute, a think tank focusing on Libya, said clashes have re-emerged because Hamza has “enormous standing amongst his brigade, the 444”.
“Also, I think he blurs the lines between the political factions that have been largely at peace for the last year in Tripoli and their allegiances towards the [Tripoli] government of national unity as it stands … And those that favour a unity government with renegade General Khalifa Haftar,” el-Gomati told Al Jazeera, referring to the ruler of Libya’s east.
“Those that are on the ground and know Hamza quite well would suggest that he is in the anti-Haftar faction,” el-Gomati said.
Have there been previous clashes?
The escalation follows months of relative peace.
In May, the same armed groups had clashed for hours in Tripoli, also after the arrest of a 444 Brigade member. Minor injuries resulted.
Tripoli has seen similar episodes of violence in recent years, although most have only lasted a couple of hours.
Last August, clashes between two other militias active in the capital killed at least 23 people.
What has the world reaction been?
The African Union expressed its concers and calls for an end to hostilities and a start to reconciliation on Thursday. Moussa Faki Mahamat, AU Commission head, “is following with great concern the developments of the security situation in Tripoli” the statement said.
The embassies of the United Kingdom and the United States in Libya both issued statements expressing their concerns about the escalating violence.
The US urged “immediate de-escalation in order to sustain recent Libyan gains toward stability and elections”.
Libya capital Tripoli rocked by militia clashes
Tensions flared between two of the Libyan capital’s most powerful armed factions. The oil-rich nation has been in a state of turmoil for over a decade.
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.