Somali pirates have captured a South Korean oil tanker off the east African coast carrying nearly $170m of crude oil from Iraq to the US.

The South Korean foreign ministry said the 333m Samho Dream, capable of carrying about two million barrels of crude oil, was hijacked and its 24 crew taken hostage, according to Reuters.

The pirates are believed to have moved the tanker to Haradheere.

US refiner Valero Energy Corporation said it owned the cargo on board the vessel.

Valero said the cargo was bound for the Gulf of Mexico.