New Delhi, Dec. 28: A tramp ship was towed into Mumbai harbour after six containers of explosives that were being sent to the Indian Border Roads Organisation (BRO) project in Afghanistan through Iran went missing from the vessel.

The incident has jolted Indian authorities, making US suspicions of piracy and terrorism in the high seas off the Indian coast appear very real.

A tramp ship is a vessel that does not ply regular routes but is available for hire.

The MV Eugenia had left Mumbai on December 22. In its cargo were six containers carrying about 100 tonnes of explosives the BRO, a wing of the Indian military, describes as “25 mm dia Cap non MG based emulsion”.

This is probably ammonium nitrate, an explosive used by road builders. A BRO official confirmed that the consignment was ordered by the general manager of the Indian project to build the Zaranj-Delaram Road in Afghanistan.

In the wrong hands, ammonium nitrate can be used to devastating effect. A truckload of the explosive was used to blast a Federal building in Oklahoma City in 1995.

A Coast Guard officer said the account given by the captain of the Honduras-registered ship was not corroborated by the circumstances and records with the Mumbai Port Trust. Owned by a Greek, the ship’s captain is a Russian, Khakhi Sergei.

The authorities are also surprised that the containers carrying the explosives were loosely lashed on the upper deck. This is usually done if the intention is to unload the consignment soon.

The officer said Sergei had said the Eugenia had encountered rough seas shortly after sailing from Mumbai. Meteorological reports do not bear this out and the Arabian Sea was said to be in one of its calmest phases.

To steady the ship, the captain is reported to have said, the crew dumped six containers into the water. The interrogators wondered why this had to be done. The ship was said to be within Indian waters.

The captain also said it took two days to steady the ship, which, too, is being doubted. The Eugenia is not a large vessel ? only 700 tonnes ? and had a crew of six, including the captain.

Defence ministry sources said investigators were not ruling out the possibility that the Eugenia offloaded its cargo to another ship. In other words, the suspicion of piracy is very strong.

This is just the kind of warning the US has been sounding to the Indian government. It has used suspicions of piracy in the busy sea-lanes off Indian coasts to urge India to join in the Proliferation Security Initiative and take on policing responsibility by boarding and searching vessels.

The ship’s crew ? four are believed to be Russians and two Myanmarese ? has been detained for questioning.