AK Antony said he felt "sad about those navy personnel who lost their lives". Earlier the navy said it feared 18 sailors had been trapped on board. 

 

The blast on the INS Sindhurakshak took place after midnight and fire-fighters spent four hours putting out the blaze. 

 

Officials said the diesel-powered vessel³ was badly damaged.

 

Mr Antony gave no further details about how many people were killed and if he was referring to deaths among the sailors still trapped on the submarine. 

 

But one navy official told the BBC that "surviving an explosion of this huge scale" was rare. 

 

Many sailors managed to jump to safety after the blast. Rescue teams are on scene and some of the injured were taken to hospital. The submarine remains⁴ partly submerged at its berth¹.

 

It is unclear exactly what caused the explosion but dramatic images on Indian television showed a large fireball illuminating⁵ the sky. Smoke from the blaze could be seen in many parts of the city.

 

A naval⁶ inquiry⁷ has been set up to look into the causes of the incident, but officials told the BBC they suspect it to be the result of an on-board error and not an act involving any outside agency.

 

The Russian-built submarine was upgraded recently at a cost of $80m.

 

Russian firm Zvyozdochka, which refitted the submarine, said the vessel had been fully⁸ operational when it was returned to India in January.

点击收听单词发音