The boat was carrying more than 150 passengers when the incident occurred Thursday, the radio operator said.
About 70 passengers survived, but five of them died of malnutrition Friday, journalists quoted Mohamed Aden Issa, an official in the coastal Somaliland village of Lasqory, as saying.
The boat left the port of Bosaso in the northeastern region of Puntland 10 days ago, the operator said. After the incident, a fishing boat towed the vessel from the Gulf of Aden to Lasqory with the survivors on board, the operator said from Lasqory, communicating by two-way VHF radio.
The crew's whereabouts were not known, according to Issa. The information could not immediately be confirmed.
Sail-powered dhows and cargo boats have been ferrying passengers across the gulf that separates Somalia and Yemen.
Hundreds of people have been trying to reach Yemen in search of work since several countries in the Persian Gulf imposed a livestock ban on Somalia following an outbreak of Rift Valley Fever in Saudi Arabia. Somalia's main export is livestock to Yemen and Saudi Arabia.
Somaliland declared independence in May 1991, four months after the ouster of Somalia's President Mohamed Siad Barre and the collapse of the central government. Puntland declared autonomy in July 1998. Neither region is internationally recognized.
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