Defence Minister A K Antony says, the Navy and the Coast Guard will step up surveillance along Kerala and Lakshadweep coast because increase in presence of pirates in the region.Addressing a press conference in Kochi this evening, Antony observed that despite the efforts of navies of several countries in the Somalilan waters, the presence of pirates indicated that other forces could be behind them.He said the Somalian pirates nabbed recently off the coast of Lakshadweep will be tried as per international law.He said India is of the view that any joint operation to tackle the pirate menace should be under the auspices of the United Nations.Antony said the process of finalising the bid for the Medium Multi Role Combat Aircraft for the IAF is underway. He said the bid will be finalised according to the country's well defined procedures for defence procurements.Terming the killing of a youth in Kashmir recently by the Army on mistaken identity as unfortunate, Antony said security forces in Kashmir work under severe stress round the clock to check infiltrations.