Pirates have seized a Ukrainian cargo vessel carrying T-72 tanks off eastern Somalia, an official said today.
Ukraine's foreign ministry said the ship had 21 crew members.
The seizure is the latest in a string of hijackings in waters near the troubled African country.
The hijacking brings the number of attacks off Somalia to 61 this year, and pirates are now holding 14 ships and more than 300 crew members, said Noel Choong, who heads the International Maritime Bureau's piracy reporting centre based in Malaysia.
Choong said pirates attacked the Ukrainian vessel yesterday. He declined to reveal the crew's nationalities or the ship's destination, citing policy.
Most pirate attacks occur in the Gulf of Aden, one of the world's busiest shipping lanes, to the north of the African country. However, yesterday's hijacking was in the Indian Ocean waters off eastern Somalia — the third in that area in recent weeks.
Choong said the United Nations and the international community should take "serious action" to prevent further attacks.
"There must be a deterrent for the pirates not to attack the ships. If there is no deterrent, it will continue," he said.
The US Naval Central Command has set up a security corridor patrolled by an international coalition of warships. However, pirate attacks remain prevalent off Somalia, which has not had a functioning government since 1991.
Some 20,000 vessels pass through the Gulf of Aden every year while traveling between the Red Sea and the Indian Ocean.Reuse content