At least 33 African migrants drowned off the Yemeni coast of Shabwa after smugglers operating the boat forced the passengers into the sea, the country spokesman of the International Organization for Migration (IOM) said.The 33 migrants were part of 360 African refugees and migrants overcrowded on-board two small boats, Xinhua news agency quoted the spokesman Saaba al-Mualemi as saying."The smugglers of one of the boats opened fire and forced the passengers to jump out of the boat a few kilometres away from the shore on Wednesday," he said, adding that some managed to swim and survived.In May, around 46 African refugees drowned off Shabwa, according to the IOM.