ROME, Shawwal 17, 1436, August 02, 2015, SPA -- Italy's coast guard said about 1,800 migrants were rescued from seven overcrowded vessels on Saturday, while five corpses were found on a large rubber boat carrying 212 others, Reuters reported. The dead bodies were found on board at the time of the rescue, a coast guard spokeswoman said on Sunday. The cause of death was not yet known, she said. The Mediterranean has become the world's most deadly barrier for migrants and refugees, with 3,500 thought to have died at sea last year and almost 2,000 so far this year. Many are fleeing poverty and violence in the Middle East and Africa. While there was no breakdown by nationality of those rescued on Saturday, about a quarter of arrivals this year have come from Eritrea, followed by Nigerians, Somalis, Sudanese and Syrians, according to the UN refugee agency. --SPA 15:34 LOCAL TIME 12:34 GMT www.spa.gov.sa/w