ROME, May 15 (Xinhua) -- Nearly 500 migrants were saved, and around 20 were feared dead in the Mediterranean on Sunday, the UN Refugee Agency (UNHCR) in Italy said on Monday.

The figures were based on latest reports by humanitarian groups involved in rescue missions to assist migrants and refugees during their sea crossing towards Europe.

Four different operations were launched in the Strait of Sicily between Italy and Libya on Sunday, the UNHCR said on its official twitter account.

484 people were rescued while sailing on board of four inflatable crafts, and about 20 were believed to have died in the journey, according to the sources.

Up to late on Monday, however, only seven bodies have been recovered. All of them belonged to male victims, Italian media reported.

"UNHCR officials are listening to survivors' testimonies," the agency added.

The four missions had been coordinated and carried out by Italy's coast guard and navy, with the help of a a humanitarian group vessel and of a commercial ship.