"Nearly 110 Ethiopian refugees are missing after the sinking on 20 March of their Ethiopian boat in a collision with a Somali boat," Muhammad Arif, representative of the United Nations High Commission for Refugees (UNHCR) in Aden, told AFP.
"The boat sank with 120 refugees aboard. Only 13 people, the majority of them crew members, were saved," he added, citing accounts by two crew members among the survivors who arrived in Yemen.
The passengers were believed to be on route to Saudi Arabia.
A village shop owner, Ismail Yasin, said the people who travelled on the ill-fated boat had been waiting for the trip to Yemen for the past three weeks.
"The accident occurred in Somalia's territorial waters ... in front of the Somali coast, two hours from Bosasso," according to the UN official.
The 110 Somali and Ethiopian passengers who were on the Somali boat involved in the collision returned to Bosasso, Aref said.
Then on March 25, they boarded two boats, along with other refugees, bound for Yemen where they arrived three days later on the coast of the Shabwa region, 360km east of Aden, he said.
According to a Yemeni non-governmental organisation responsible for all refugees from the Horn of Africa, eight Somalis among those who boarded one of the boats that left Bosasso on 25 March died on that journey.
Conflicting reports said the boat may have capsized, while others said the travellers could have been forced to jump into the sea before the boat reached the Yemeni coast and were unable to swim ashore.
Heavily armed Somalis, who transport these people in overloaded boats, normally order them to jump out of the boats before reaching the coast and force them to swim ashore to avoid arrest by Yemeni security forces.
Most people reached in Bosasso said the villagers learned of the tragedy after telephoning relatives in Yemen, who said the boat had not reached its destination.
Thousands of Somalis fleeing poverty and violence in their country since dictator Muhammad Siad Barre was overthrown in 1991 brave the perilous Somalia-Yemen sea route every year.
In January 2003, between 80 and 100 people, most of them Somalis, died after their boat capsized in the Gulf of Aden. According to local humanitarian sources in the region, there are currently 40,000 Somali refugees in Yemen.