Diplomatic stand-off: Italian ambassador to Dehli Daniele Mancini has been ordered to stay in India.
Delhi: India's top court has told the Italian ambassador to Delhi not to leave the country without its permission, as protests escalated over Italy's decision to block the return of two marines charged with killing fishermen.
A bench headed by Supreme Court Chief Justice Altamas Kabir imposed the curb on envoy Daniele Mancini and requested he explain the Italian government's move by Monday.
Last month, the court allowed the marines to leave India to vote in Italy's election following an undertaking from Mr Mancini that they would be sent back within four weeks.
''Under the Vienna convention, the ambassador may claim diplomatic immunity and decide not to respond to the notice,'' Sanjay Hegde, an advocate in the Supreme Court, said.
The diplomatic stand-off between the two nations over the fate of the men has steadily intensified.
Indian Prime Minister Manmohan Singh said on Wednesday there would be ''consequences'' for bilateral ties if Italian authorities in Rome did not ''keep their word''.
The marines were guarding the Italian-flagged Enrica Lexie tanker on its journey to Egypt from Singapore, a route that includes crossing the Indian Ocean, where Somali pirates operate.
Italy has argued that the men shot the two fishermen in self-defence suspecting them to be pirates, and that the marines should be tried in their own country because the killings occurred in seas outside of India's jurisdiction.
India says the attack happened in its territorial waters off the southern state of Kerala.
''Everything that is necessary to ensure the dignity and the primacy of India in this matter will be preserved,'' Foreign Minister Salman Khurshid told reporters in Delhi on Thursday.
''This is a matter that will be treated with greatest urgency. We have to take steps.''
On Tuesday, India summoned Mr Mancini to protest his government's decision.
The attempted prosecution of the Italians is the first to hold armed maritime guards accountable for the deaths of innocent people in an anti-piracy operation.
Relations between the two countries were further strained by allegations bribes were paid by the AgustaWestland unit of Italian company Finmeccanica to secure the contract to supply 12 civilian helicopters to the Indian government.
Mr Mancini told Indian authorities marines Massimiliano Latorre and Salvatore Girone ''won't return to India'', Italy's Foreign Ministry said on Monday.
The Italian government said India failed to respond to a request to negotiate a diplomatic solution.
Ferrari, the Italian sports car maker, even weighed in, having two of its cars carry the flag of the Italian navy during the October 28 formula one race in Delhi.
India's Chief Justice ruled in January that the two men could be put on trial, ordering hearings before a specially convened court in the capital.