Two Italian marines charged with killing two fishermen in India will remain in Italy because of an international diplomatic row.

Massimiliano Latorre and Salvatore Girone, who are accused of shooting dead two fishermen they say they mistook for pirates, returned to Italy to vote in the February parliamentary elections.

"We are happy to be back home. This has been possible because India's supreme court has shown itself to be very democratic by recognising our right to vote," Latorre said.

The shooting caused a serious diplomatic row, with Rome claiming that India had snubbed Italian requests for a diplomatic solution.

But the stakes have been raised even further after the Italian government said that its two nationals would remain in their home country and not return to India to face trial.

"Italy has informed the Indian government that, given the formal initiation of an international dispute between the two states, the marines will not return at the end of their home leave," said Italy's foreign minister Giulio Terzi.

"Italy always maintained that the Indian authorities' behaviour violates international law, in particular, it violates the right of immunity from the foreign country's judicial system."

He said that Italy was still prepared to work out a deal, "even with an international sentence or a judicial resolution".

In February, India's supreme court ruled that India had the judicial right to try the marines, setting the stage for a criminal trial. Rome had argued that the shooting, which was off the coast of Kerala, southern India, had taken place in international waters.

The suspects were allowed by a Kerala court to spend Christmas with their families in Italy providing they returned to India by 10 January, a condition that they followed.

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