Twelve people have been confirmed dead and another 28 remain missing after they were forced overboard by human smugglers in the Gulf of Aden, the U.N. refugee agency said on Tuesday. The 40 people were among a total of 115 passengers, mostly Somalis and Ethiopians, on a boat which departed from northern Somalia and headed for Yemen, said U.N. High Commissioner for Refugees (UNHCR) spokesman Ron Redmond. On Sunday, as the boat was within sight of the Yemeni coast but still in deep water, the smugglers threw the 40 mostly Ethiopian people overboard because they did not or could not pay extra, according to survivors of the dangerous journey, the agency reported. Twelve bodies have so far washed up on the beach and 28 remain missing, Redmond said. The remaining 75 boat passengers survived and have arrived in a UNHCR reception center in Yemen where they are receiving help, he added. Over 600 African migrants have been reported dead or missing so far this year trying to cross the Gulf of Aden from Somalia to Yemen in smugglers' boats, according to UNHCR figures. During the first 10 months of this year, over 38,000 people made the crossing compared with 29,500 who made the same journey during the whole of 2007, UNHCR said.