the aircraft carrier to impose a naval blockade of East Pakistan. The war saw the first offensive operations undertaken by the Indian Navy against an enemy port, when Karachi harbour was attacked twice during Operation Trident (1971) and Operation Python. These attacks destroyed a significant portion of Pakistan's naval strength, whereas no Indian ship was lost. The Indian Navy did, however, lose a single ship, when INS Khukri (F149) was torpedoed by a Pakistani submarine. 13 days after the invasion of East Pakistan, 93,000 Pakistani military personnel surrendered to the Indian Army and the Mukti Bahini. After the surrender of Pakistani forces, East Pakistan became the independent nation of Bangladesh. Kargil War During the winter months of 1998–99, the Indian army vacated its posts at very high peaks in Kargil sector in Kashmir as it used to do every year. Pakistani Army intruded across the Line of Control and occupied the posts. Indian army discovered this in May 1999 when the snow thawed. This resulted in intense fighting between Indian and Pakistani forces, known as the Kargil conflict. Backed by the Indian Air Force, the Indian Army regained many of the posts that Pakistan had occupied. Pakistan later withdrew from the remaining portion under international pressure and high casualties. Other territorial claims The relations are locked in other territorial claims such as the Siachen Glacier and Kori Creek. Water disputes The Indus Waters Treaty governs the rivers that flow from India into Pakistan. Water is cited as one possible cause for a conflict between the two nations, but to date issues such as the Nimoo Bazgo Project have been resolved through diplomacy. Bengal refugee crisis (1949) In 1949, India recorded close to 1 million Hindu refugees, who flooded into West Bengal and other states from East Pakistan (now Bangladesh), owing to communal violence, intimidation and repression from authorities. The plight of the refugees outraged Hindus and Indian nationalists, and the refugee population drained the resources of Indian states, which were unable to absorb them. While not ruling out war, Prime Minister Nehru and Sardar Patel invited Liaquat Ali Khan for talks in Delhi. Although many Indians termed this appeasement, Nehru signed a pact with Liaquat Ali Khan that pledged both nations to the protection of minorities and creation of minority commissions. Khan and Nehru also signed a trade agreement, and committed to resolving bilateral conflicts through peaceful means. Steadily, hundreds