Libya's coastal guard rescues illegal migrants trying to leave in small boats bound for Italy. Picture: File picture: Santi Palacios/AP

Rome - Twenty-one people are feared dead and 72 have been rescued following migrant rescues in the central Mediterranean, the SOS Mediterranee aid group said on Tuesday.

The survivors are being taken to the Sicilian port of Pozzallo, the non-governmental organization, which runs a rescue boat with Doctors Without Borders (MSF), said in a tweet.

Late on Monday, SOS Mediterranee said there was one pregnant woman and 14 children with no family among the survivors. The organization said they come mostly from West Africa.

The migrants were first rescued last week by a Cypriot merchant ship, and handed over to SOS Mediterranee late on Saturday.

Thirty were on a sinking wooden boat, and according to survivors, 21 people died in that shipwreck. "There were five women on board, four drowned, including a pregnant one. I lost my brother," a Gambian man was quoted as saying by SOS Mediterranee.

Another 42 jumped out of a dinghy before it was intercepted by the Libyan coastguard, which has received training and funding from Italy and the EU to stop migrant departures.

Most migrants are desperate not to be returned to Libya, where they face widespread abuse and torture. According to SOS Mediterranee, the Libyan coastguard picked up about 90 people from the dinghy.

The Mediterranean is the world's most dangerous sea migration route. According to the International Organization for Migration, 421 people have died or gone missing in its waters since the start of the year.