As many as 65 people died off the shores of Yemen when one smugglers' boat capsized, another sank and would-be migrants were beaten to death and asphyxiated on a third, the United Nations refugee agency said on Tuesday.

The three separate incidents took place in the Gulf of Aden on Sunday and Monday, said Melissa Fleming, chief spokeswoman for the UN High Commissioner for Refugees.

So far this year, UNHCR estimates that nearly 44,000 people have made the journey to Yemen from the Horn of Africa, where political instability, violence, famine and poverty are spurring a dangerous sea exodus.

Fleming said engine failure on the first vessel prompted the smuggling crew to jump overboard, causing it to capsize. Ninety-eight people managed to swim to shore and 43 are missing and presumed dead.

One person was reported to have suffocated in the engine room of that boat, which picked up passengers from Somalia, in a town west of Bossasso. "Passengers were repeatedly beaten and threatened by the smugglers during the journey," Fleming said.

On the second boat, carrying 112 Africans from Somalia to Yemen, some passengers were held in the engine room. Three were beaten to death there and the other 10 died of asphyxiation, according to the UNHCR, which cited survivor testimony.

Fleming said that 38 people were rescued from a small boat sinking in deep waters that was sighted by a European Union warship. "Another six people are missing and presumed drowned," she told a Geneva news briefing.

Some 860 smugglers' ships have crossed the Gulf of Aden this year, with many migrants intending to make their way through Yemen to neighbouring Saudi Arabia and Oman in search of work. Fleming said there appear to be "an increasing number of larger vessels making the journey," putting more lives at risk. - Reuters