The Pakistani government confirmed today that it would consider any attempt by India to cut off water supplies from the Indus River as an act of war.A statement issued by the office of Prime Minister Shehbaz Sharif, following a meeting of the National Security Committee, said that any attempt to block or divert the flow of water to which Pakistan is entitled under the Indus Waters Treaty would be deemed an act of war and would be met with a strong response.Earlier today, Pakistan announced the closure of its airspace to Indian airlines and rejected New Delhi's suspension of the water-sharing treaty, following an armed attack two days ago targeting a group of tourists in the Indian-administered part of the disputed Kashmir region.These measures from Islamabad come in response to the Indian government's announcement of the closure of the main land border crossing with Pakistan. India also ordered all Pakistanis residing in its territory to leave within 48 hours and reduced the staff of the Pakistan High Commission in the country from 55 to 30 personnel.At least 24 people were killed in the armed attack on a group of tourists in the Indian-administered part of Kashmir, and New Delhi authorities accused Pakistan of involvement in the incident.The Indus Waters Treaty is considered one of the oldest water agreements in the world. It was signed under the auspices of the World Bank between India and Pakistan following their independence, to share the waters of six major rivers that originate in the Himalayas and flow across the borders of both countries.Under the treaty, India received full rights to use the eastern rivers, while Pakistan was granted control over the western rivers, which serve as the agricultural and economic lifeline of the country.