A Yemeni court in the southeastern coastal city of Mukalla on Monday sentenced 16 Somalis to 10 years in prison after convicting them of piracy in Yemen's territorial waters, the state-run Saba news agency reported.
Another Somali received five-year term in jail over the same charge.
The defendants were convicted of hijacking a Yemeni fishing boat along with its crew in the Yemeni territorial waters in the Gulf of Aden.
Saba did not provide details on the date of their arrest.
The Yemeni authorities have arrested dozens of Somalis over charges of piracy throughout the past two years.
In May 2012, Yemen said it captured 14 Somali pirates off the country's island of Socotra in the Gulf of Aden.
About 25,000 ships pass through the Gulf of Aden every year. The water off the northern coast of Somalia is ranked as the highest risk area of piracy in the world.