(Adds background, Napolitano comment)
ROME, March 21 (Reuters) - Two Italian marines accused of killing two Indian fishermen while on anti-piracy duty will return to India on Friday, the Italian government said, reversing a previous decision not to send them back to face trial after a home visit.
"The Italian government requested and received written assurances from the Indian authorities regarding the treatment of the marines and the protection of their fundamental rights," the government said in a statement.
The Italian Foreign Ministry sparked fury in India earlier in March when they said the marines, Salvatore Girone and Massimiliano Latorre, would not return to India after being granted home leave to let them vote in last month's election.
India's Supreme Court subsequently ordered the Italian ambassador not to leave the country, escalating the stand-off and spurring European Union foreign policy chief Catherine Ashton to warn that India was violating international law.
The marines, part of a military security team protecting the tanker Enrica Lexie from piracy, are accused of shooting dead two fishermen in February 2012, apparently after mistaking them for pirates in waters off the southern Indian state of Kerala.
Girone and Latorre said they fired warning shots only.
They were detained in India to face trial, but the Supreme Court allowed them to go home for four weeks to vote in a parliamentary election on Feb. 24-25, provided they returned to India by Friday.
Italian President Giorgio Napolitano called Latorre to tell him and Girone that he "appreciated the sense of responsibility demonstrated in their acceptance of the government's decision", according to a statement.
Napolitano assured the two marines that the Italian state would be "by their side in the path that awaits them" and that he hoped for "a correct recognition of their point of view". (Reporting by Catherine Hornby and Steve Scherer; editing by Mark Heinrich)