Defence Minister A.K. Antony has expressed serious concern over supply of modern weapons to Pakistan by the US. Talking to reporters after inaugurating Indian Coast Guard Complex at Vishinjam, near Thiruvananthapuram yesterday, he said New Delhi has urged the US to see that the modern weapons provided to Pakistan to fight terrorist outfits like Al-Qaeda and Taliban in Afghanistan are used properly and not against India. He said India's past experience is bitter on the issue and the Defence Department is taking the issue very seriously.