Ships and a submarine belonging to the Indian Navy are seen docked at the naval dockyard in Mumbai.
Ships and a submarine belonging to the Indian Navy are seen docked at the naval dockyard in Mumbai.Reuters

An Indian submarine exploded in a military dock in Mumbai early Wednesday, resulting in a huge fire and killing navy personnel on board.

Defence Minister AK Antony confirmed the death of sailors on board the diesel-powered INS Sindhurakshak, which is located between Lion Gate and Seta Gate in the weapon's bay.

"I feel sad about those navy personnel who have lost their lives in service of the country," he told reporters on Wedneday, but held back on revealing the number of casualties in the explosion. 

Initial reports said that 18 sailors were trapped in the vessel and three other officers missing. Rescue and search operations are still ongoing.

Officials rushed some of the injured to the Indian Naval Hospital Ship, but it remains unclear if these sailors were from the gutted vessel. 

The fierce explosion occurred shortly after midnight at the high-security naval dockyard and was heard ashore. Over a dozen fire tenders from the Naval Dockyard and Mumbai Fire Brigade rushed to the spot and managed to douse the flames by 3 am. NDTV released a grainy footage of the explosion which lit up the skyline above the dockyard. All other vessels located close by were pulled to safety.

The impact of the blast had caused the vessel to partially sink. "The submarine has submerged at her berth with only a portion visible above the surface," the Navy said in a statement.  

The cause of the explosion is still not known and a Board of Inquiry will soon launch an investigation.

According to CNN-IBN, preliminary reports suggest that the explosion may have been triggered by the presence of explosive material in the ship. The submarine was recently refurbished in Russia for $18 million dollars and was fitted with improved weaponry.

The incident took place at a time when preparations are in full swing for Independence Day. Military operations across the country are now on high alert, fearing any untoward incidents during celebrations on Thursday.

Just days ago, India had launched sea trials for its first nuclear submarine, INS Arihant, highlighting its ambition to take over China's rising influence over the Indian Ocean.