Survivors said a total of 47 people reached shore after the incident and later saw Yemeni authorities burying five bodies, according to the UNHCR.

The boat left the Somali port of Marera near Bossaso on Monday and sailed for three days before the passengers were forced overboard.

Bodies washed ashore

A Yemeni security official told the Associated Press news agency on Friday that 30 bodies had been washed ashore but it was not clear if they were from the Somali vessel.

Bodies often float up on the coast of Shabwa province, about 500km south of the capital Sanaa. During the first half September, some 165 bodies were found on the shore and buried, according to the interior ministry.

The UNHCR has said that about 32,000 people have arrived in Yemen by boat this year, many of them from the Horn of Africa. A statement form Yemen's interior ministry said 22,532 Somali migrants have reached the country in 2008.

"We are seeing a big surge of people arriving in Yemen, many of them seeking refuge in our camps. We have appealed for $17m to fund the relief programme, to provide shelter, water and other assistance," Kessler said.

Smugglers charge between $70 and $200 to carry a person on the perilous journey across the Gulf of Aden, but reports of abuse by the traffickers are common.

At least 52 Somali nationals died in similar circumstances in September, according to the UNHCR.