An explosion followed by a massive fire ripped through a Singapore-flagged container ship with 13 Indian crew including the captain off Agatti Islands, the Coast Guard said on Wednesday. Four crewmen, including an Indian, are reported missing.

Casualties are feared in the disaster that struck on the high seas around 9.45 p.m. on Tuesday. The cause of the incident, which occurred off the south-west coast of India, is not yet known, the official said.

The Coast Guard’s Maritime Rescue Coordination Centre (MRCC) at Mumbai said it received a distress call from the Singapore-flagged container cargo ship “Maersk Honam”.

The vessel had left Singapore on March 1, on way to the Suez in Egypt, and had a crew of 27 including 13 Indians.

The captain is an Indian. The remaining crew are from the Philippines, Britain, Romania and Thailand.

At the time of the distress call, the ship carrying unspecified cargo in 7860 TEU containers was at a distance of around 650 NM (1,300 kms off west of Kochi, near the Agatti Isles in Lakshwadeep Islands.

Coast Guard Inspector General K.R. Nautiyal, the Coast Guard Commander (West), said: “Search Operations are on.

“It is our priority to save and rescue the four missing crew and also continue our efforts to salvage the vessel with assistance of specialised vessels, which is being arranged in co-ordination with the ship agency,” he added.

The Indian Navy launched a Boeing P8i aircraft from Tamil Nadu to search for the missing crew. The MRCC alerted all merchant ships near the location.

A merchant navy ship, MV Als Cicero, which reached Maersk Honam at about 11.25 p.m., reported that the container vessel was consumed in flames.

The crew had earlier abandoned the ship as the fire spread beyond their control.

Maersk Honam had 27 crew, out of which 23 have been rescued by Als Cicero. The remaining four include an Indian and others whose nationality is not clear.

Coast Guard ship Shoor, patrolling near Lakshadweep Islands, was diverted to assist the distressed vessel. Shoor is an offshore patrol vessel with sophisticated firefighting equipment.