NEW DELHI — A gas leak on a naval vessel has killed five soldiers taking part in an exercise in the Bay of Bengal, the Indian navy said on Saturday.

The sailors died due to the "inadvertent inhalation of hydrogen sulphide gas," the Indian navy said in a statement, adding three others were ill after breathing in the gas.

The cause of the accident late Friday on troop-carrier INS Jalashwa was not immediately known.

The Indian navy bought the vessel -- previously called the USS Trenton -- from the US Navy last year.