The Indian Navy has ordered a high-level probe into all submarine mishaps in the past one year, including Wednesday's fire accident on board Russian-origin Kilo Class submarine INS Sindhuratna off Mumbai coast, in which two officers were killed and seven sailors injured.

"A high-level inquiry headed by an officer of Rear Admiral rank has been constituted and has immediately commenced its proceedings to establish the cause of all (submarine) incidents and to recommend steps for continuing safe operations of submarines," the Indian Navy said in a statement.

In fact, Wednesday's submarine incident -- in which smoke, triggered by fire, engulfed the vessel on the Arabian Sea, some 50 km off Mumbai coast -- was the 10th mishap involving an Indian Navy warship and the third submarine mishap in the past seven months.

In August last year, naval submarine INS Sindhurakshak sank at Mumbai port after it caught fire following multiple explosions on board, killing 18 sailors.

Sources say India currently has 13 conventionally powered submarines, out of which at least five have already exceeded their design life.

The INS Sindhughosh, INS Sindhudhaj, INS Sindhuraj, INS Sindhuvir and INS Sindhuratna -- all Russian-origin Kilo Class submarines, were inducted into the Indian Navy between 1986 and 1988. They have exceeded their shelf life.

Even the recent purchases of the Kilo Class fleet date back to 2000 when the INS Sindhushastra was bought. The INS Sindhurakshak was acquired in 1997.

"The Indian Navy has long complained of delays in submarine fleet modernization. India also does not have a submarine rescue vessel. But the Indian government has been apparently slow in its approach in the modernization drive of the naval vessels," said the sources.

Indian media has also been speculating that Indian Navy chief Admiral D.K. Joshi, who resigned hours after the latest submarine mishap, taking moral responsibility, was actually "very, very upset" about the government's lack of pace in modernizing the aging naval fleet.