The modifications in the anti-ship Harpoon missiles is a provocative and destabilising action by Islamabad and threatens the "delicate" India-Pakistan ties, an influential US lawmaker has said. "If (recent media reports are) true, the modification of these missiles would be a violation of the Arms Export Control Act. In addition, this would be yet another provocative and destabilising action which threatens the delicate relationship between India and Pakistan," Congressman Edward Markey has said. Amidst reports appearing in the US media, which has been confirmed by the US Administration, that Pakistan has illegally modified the American-made Harpoon missiles to expand its striking capability, Markey, sought off a letter to the Secretary of State Hillary Clinton expressing his concern. Though Islamabad has denied the charges, the US has said that it has entered into an agreement with Pakistan for a mutually agreed inspection of the missiles in questions. Markey, founder of the House Bipartisan Task Force on Nonproliferation, in a letter to Clinton sought information on published reports that Pakistan may have illegally modified US-exported Harpoon missiles to give them a land-attack capability. "The nascent nuclear arms race between India and Pakistan is extraordinarily worrisome, as both countries appear to be increasing their ability to manufacture weapons," Markey wrote in the letter.