Almost 100 migrants were rescued off Libya's west coast on Sunday as they made failed attempts to reach Europe, while around 20 were missing, AFP reporters and the coastguard said.

The Libyan coastguard rescued the mostly African migrants as they attempted perilous sea crossings to Italy and brought them to a naval base in the capital Tripoli, where they were met by a team from the International Organization for Migration (IOM).

The majority of the migrants were from Cameroon, Sudan and Mali, an IOM representative said.

The survivors included six women and two children. Two people in critical condition were transported to hospital in the Libyan capital.

Some 20 people were still missing, according to the coastguard.

"The additional tragedy is that in most cases, there is very little search to recover the bodies of those who drown," Safa Msehli, IOM spokesperson in Geneva, told AFP. 

"The sight of bodies washing ashore later has become too familiar."

More than 1,200 migrants and asylum-seekers died while crossing the Mediterranean in 2020, according to the IOM.

On Saturday, German charity Sea-Watch said it had saved nearly 150 migrants off the Libyan coast in two operations.

International agencies frequently denounce the return to Libya of migrants intercepted at sea due to the chaotic situation in the country and poor conditions in detention centres.

"At least 3,700 men, women, and children, were returned to (Libya) this year," the IOM said Friday on Twitter.

"Most were taken to detention, where already dire conditions continue to worsen."