Two sailors are still missing on the accident-hit INS Sindhuratna submarine, official sources said Thursday.

An official said the condition of the submarine has been described as safe.

“We shall attempt to open the sealed compartments where the two missing sailors are believed to be trapped and hope to rescue them,” the official, requesting anonymity, told IANS.

Seven Indian Navy personnel were injured and two went missing early Wednesday after smoke filled up a compartment aboard the INS Sindhuratna submarine.

The official declined to speculate on the fate of the two missing sailors whose whereabouts remained unclear more than a day after the incident in the high seas.

There were 94 sailors onboard when the accident took place in the sailors’ accommodation area in compartment No. 3.

While the sailors battled the smoke, seven who inhaled the toxic fumes had to be airlifted in unconscious state to Mumbai for treatment and their condition is now stable.

The accident – the cause of which is not yet clear – took place in the early hours of Wednesday, about 50 nautical miles (80 km) in the Arabian Sea.

Refitted and renovated in Mumbai last December, the INS Sindhuratna was on a routine training exercise to familiarize the crew with operations of the Russian built vessel.

The vessel was underwater at the time of the incident and it was not fitted with weapons of any kind as it was on a training and familiarization mission.

The Indian Navy has ordered an inquiry into the incident – the tenth in recent times – which has hit its elite fleet of submarines.