A group of 93 asylum seekers stuck in Libya were evacuated to Italy on Thursday in the first flight of its kind in two years, the UN refugee agency said.

The flight to Rome is one of five planned evacuation airlifts organised by the UN High Commissioner for Refugees, or UNHCR.

A total of 500 asylum seekers would be evacuated over a year "under a new mechanism for humanitarian admissions", the agency said in a statement.

The last evacuation flight to Italy was in 2019.

Those flown out of Tripoli on Thursday included "children, women at risk, survivors of violence and torture, and people with serious medical conditions", the UNHCR said.

"We are pleased to see these evacuation flights become a reality and that the Libyan authorities have supported them," Jean-Paul Cavalieri, the UNHCR's chief of mission in Libya, was quoted as saying in the statement.

He described the flights as "a lifeline for some of the most vulnerable asylum seekers".

"Conditions in Libya remain dire for many refugees," Cavalieri added, calling on the international community to open up other humanitarian routes.

Libya plunged into chaos and conflict after dictator Moamer Kadhafi was ousted in a NATO-backed uprising in 2011, becoming a crossroads for migrants south of the Sahara who were desperate to reach Europe.

Many of the migrants have been detained in the country, some of them in conditions condemned as deplorable by the UN and rights organisations.

In late October, Libya authorised the resumption of humanitarian flights that had been suspended for nearly a year, allowing dozens of refugees and asylum seekers to relocate to other countries.

The UNHCR also operated evacuation flights for those who wished to be resettled back in their home countries voluntarily.

On November 4, the agency evacuated 172 asylum seekers from Libya to Niger, as part of its emergency transit mechanisms, whereby they are hosted in the country until their refugee claims are processed.

Since 2017, the agency has evacuated or resettled some 6,919 refugees and asylum seekers who were in Libya. Of those, a total of 967 were evacuated to Italy.