Violation of safety regulations could be the most likely cause of the explosions on submarine Sindhurakshak, because of which it sank, Russian Deputy Prime Minister Dmitry Rogozin has said.
Rogozin, who was quoted by Russia's official news agency Itar Tass, has said India had raised no questions over the technical aspects of the submarine built and recently overhauled by Russia.
Quoting experts, he told the news agency that the violation of safety regulations was the most probable cause of the accident on Wednesday.
He qualified his comments, saying that assessments about what really happened are still being made to determine the exact reason behind the tragedy, in which 18 navy officials are feared dead.
"But things are still to be assessed in full. At the moment, we are not blaming the equipment," Rogozin said.
"The very first information that I received at night, several hours after that accident, was that the blast had occurred in the section where storage batteries were being charged. This is the most dangerous work, which is connected with safety measures rather than with the producers of this equipment," he said.
He said the submarine itself, which had covered 15,000 nautical miles, did not attract criticism about its technical characteristics.
"It has never raised any questions on the part of our Indian colleagues," he added.
The diesel-electric submarine was built in 1997 by the Admiralteiskie Verfi shipyard in St Petersburg.
It underwent interim overhaul and modernisation at the Russian Severodvinsk-based Zvezdochka shipyard, and arrived at the Mumbai port on April 29.