(By Kate Carlisle)New Delhi, March 15 - The Indian interior ministry notified all the country's airports Friday about a supreme court travel ban on the Italian ambassador amid a row over two Italian marines accused of killing two fishermen who failed to return to India as promised earlier this week. The court slapped the ban, lasting until March 19, on Ambassador Daniele Mancini after the Italian government's decision not to send the marines back to India after they were granted a permit to come home to vote in last month's general elections. In its letter to the Italian ambassador, the Indian Supreme Court said Mancini "violated" a "sworn declaration" presented on February 9 to the Indian government as "a guarantee of the marines' return". Along with the order to not leave the country, the Supreme Court ordered the ambassador to offer explanations for Italy's actions by March 18. Italian diplomats union SNDMAE said Friday that the India government is holding the Italian ambassador to New Delhi hostage, violating the Vienna Convention on diplomatic relations, specifically article 44, which it said aims to stop diplomats "being taken hostage while carrying out their duties, as is happening to Ambassador Mancini". An earlier deal, which allowed the marines to return to Italy for Christmas, was respected by both governments and was seen as a positive step - as well as a sign of goodwill - towards a diplomatic solution. In other moves, India on Friday put on hold the procedure for its new ambassador to Rome, saying it had reduced its diplomatic mission in Italy. Newly appointed Indian Ambassador Basant Kumar Gupta was scheduled to leave for Rome on Friday, but did not. Spokesmen for High Representative of the European Union for Foreign Affairs and Security Policy Catherine Ashton declined to discuss what was said to the EU's ambassador to New Delhi, Joao Cravino, who was summoned to the Indian foreign ministry Thursday. After first issuing a "no comment," later on Friday EU said it hoped for a "common solution" to the dispute between India and Italy. "The EU is taking note of the disputes between India and Italy and continues to hope that a common solution can be reached through negotiation," said a spokesperson for Catherine Ashton, EU foreign affairs representative. United Nations Secretary General Ban Ki-moon also called for a "peaceful resolution and respect for international law" on Friday. The Italian foreign ministry advised Italians in India to show "prudence" amid probable street protests against Italy's refusal to send back the two anti-piracy marines. An advisory on the 'viaggiaresicuri' (travel safe) Website said Italians in India or planning a trip there should try to keep away from any protests, especially in the southern state of Kerala where the fishermen came from. The marines, Massimilano Latorre and Salvatore Girone, who had been held in India since February 2012, were allowed to return to Italy for one month for national elections held February 24-25. Latorre and Girone, who are charged with homicide for allegedly shooting the fishermen while on an anti-piracy mission, were supposed to return to India later this month. The Italian government has always denied that India has jurisdiction over the matter, as the incident took place in international waters off the country's coast. Italian Foreign Minister Giulio Terzi on Thursday said Italy's decision to not return the pair was legitimate and Italy had a strong case which it wanted to put to independent arbitration. "We have a very solid position, of which we are perfectly convinced, (as are) many important partners in the international community, (based on) the fact that we are acting in full respect of international law," Terzi said.