New Delhi, March 12 - India on Tuesday expressed its "firm disapproval" of Italy's decision not to send back to trial in India two anti-piracy marines accused of homicide there in 2012. On Monday the Italian government announced that Massimiliano Latorre and Salvatore Girone, accused of killing two Indian fishermen, would not be returning when a four-week permit to exercise their right to vote in last month's general elections expired. India's response Tuesday came after the Italian ambassador to New Delhi, Daniele Mancini, was summoned by the Indian foreign ministry to explain Italy's decision. In a statement, the Italian foreign ministry has said that "the conduct of Indian authorities violated international rights" by detaining them for over a year. Italy has also expressed openness to the possible intervention of an international arbitrator in the case.