After a brief lull, pirates hijacked a Greek-owned oil tanker in the Arabian Sea with a crew of 15, mostly Indians and Filipinos.
The Liberian-flagged Smyrni, carrying 135,000 tons of oil, was seized off the coast of Oman, the company said, in new indications that Somali pirates are operating close to Indian shores.
The company said it lost contact with the crew at 11:50 GMT (16:20 IST) on Thursday, BBC reported.
The tanker was reported to be heading for Somalia. Pirates based on the coast of northern Somalia prey on vital international shipping lanes in the area.
The hijacking is thought to have happened about 630 km from the Omani coast. This was only the second voyage for the tanker, which first set to sea in 2011.
It is reported to have a crew of about 15 on board, composed of Indians and Filipinos. The tanker's capture comes after a recent fall in the number of hijackings in the region.
The drop has been attributed to plans by several countries to allow ships using their flags to sail with armed guards.
It has not been reported, however, whether the Smyrni had such guards on board. EU naval ships are currently on patrol off the Horn of Africa in an effort to protect vessels.
Pirates in Somalia, which has no effective central authority, often receive millions of dollars in ransom in return for hijacked ships.
According to the International Maritime Organisation, 17 ships and close to 300 crew are currently held by Somali pirates.