Rome, March 13 - If the Italian authorities "do not keep their word" and refuse to send back the two Italian marines charged with killing two Indian fishermen, "there will be consequences," Indian Prime Minister Manmohan Singh said on Wednesday. Already strained relations between Rome and New Delhi notched up on Monday when the Italian government announced that marines Salvatore Latorre and Massimiliano Girone would remain in Italy and not return to India after being allowed to come home to vote in February's general election. The marines have been at the centre of a diplomatic row between Italy and India for shooting Jelestine Valentine and Ajesh Binki during an international anti-piracy mission off the southern Kerala coast in February 2012. Kerala Chief Minister Oommen Chandy, the southern Indian state where the incident took place in February 2012, travelled to New Delhi on Wednesday to ask the prime minister for "strong action" and said that there could be "no compromise" on the marines return to India. Latorre and Girone were also allowed to return home for the Christmas holidays and went back to India after their leave ended. Italy had pledged to do so in this case as well but the foreign ministry announced that the two would not be returning to India on March 23 as scheduled.