A bitter dispute over limited water resources is fueling India-Pakistan tensions at a time when the South Asian neighbors are trying to rebuild trust and resume peace talks.
It's a long-running feud that has worsened in recent months as a dry spell focuses attention on Pakistan's growing water shortage. Three days of talks in March ended with both sides trading barbs and failing to reach a resolution.
The issue was raised Thursday when the leaders of the two countries met at a regional summit in Bhutan and agreed on the need to normalize relations, the Pakistani side said.
Further complicating the situation, Islamic extremists are trying to capitalize on allegations that India is stealing water from glacier-fed rivers that start in the disputed territory of Kashmir.
Independent experts say there is no evidence to support those charges, but they warn that Pakistani concerns about India's plans to build at least 15 new dams need to be addressed to avoid conflict.
"If you want to give Lashkar-e-Taiba and other Pakistani militants an issue that really rallies people, give them water," said John Briscoe, who has worked on water issues in the two countries for 35 years and was the World Bank's senior water adviser.
Farmers in Pakistan's central breadbasket are certainly angry.
"India has blocked our water because they are our enemy," said Mohammad, a 65-year-old farmer in the town of Gujrat who goes by only one name.
His farm sits a few miles (kilometers) from the Chenab River, which residents say has been shrinking since India completed a hydroelectric dam in its part of Kashmir in 2008. In some sections, water flows in only a tenth of the river bed, and nearby irrigation canals have dried up.
Indian officials blame any reduction on natural variation and climate change, which have hurt India as well. They add that Pakistan's antiquated irrigation system wastes large quantities of water.
"Preposterous and completely unwarranted allegations of stealing water and waging a water war are being made against India," the Indian ambassador to Pakistan, Sharat Sabharwal, said in a speech in April.
The animosity over water could make it more difficult to resolve the signature dispute between the two countries: the decades-long struggle over Kashmir.
The United States has been seeking to reduce India-Pakistan tensions, hoping that would free Pakistan to move troops away from the Indian front to fight militants attacking U.S. and NATO troops in Afghanistan from sanctuaries near the Afghan border.
"The issues of Kashmir and terrorism are going to be much more difficult if we don't have an agreement on water," said water expert Briscoe, now a professor at the Harvard School of Public Health.
The origin of the water dispute can be traced to the creation of Pakistan and India in 1947, when the British Indian empire was partitioned. The split gave India control of the part of Kashmir that is the source of six rivers that irrigate crops in Pakistan's agricultural heartland of Punjab province and elsewhere.
Under a 1960 agreement, Pakistan has the use of the three western rivers -- the Indus, Jhelum and Chenab -- and India, the three eastern ones -- the Sutlej, Beas and Ravi.
India was granted limited use of Pakistan's rivers for agricultural purposes, plus the right to build hydroelectric dams, as long as they don't store or divert large amounts of water.
Pakistan is one of the driest countries in the world, and water availability per person has fallen from about 5,000 cubic meters (175,000 cubic feet) in 1947 to around 1,000 cubic meters (35,000 cubic feet) today. Most of the drop is a result of rapid population growth, but recent shortages have heightened suspicion about India.
Pakistan's Indus water commissioner, Jamat Ali Shah, doesn't accuse India of stealing water, but he says India isn't providing information required under the 1960 pact to prove that it's not.
"There should be nothing in the track record that shows India has violated the treaty," said Shah. "But it is a fact that the track record is not clear."
India denies any intention to cut off water to Pakistan and maintains that it has complied with the treaty. But as with other issues between the two countries, mistrust runs high.
"If he has the capacity to hurt me, the best that can be said about him is that he will use it for blackmailing and the worst is that he will use it to harm me," said Shams ul Mulk, the former head of Pakistan's Ministry of Water and Power.
Briscoe said the dams India is planning to build could give it the ability to choke off water to Pakistan if it wanted to pressure its neighbor.
India should provide automatic flow data to Pakistan, he said, while also warning that heated rhetoric on the Pakistan side would only embolden extremists.
Jamaat-e-Dawa, an alleged front group for the militant Lashkar-e-Taiba organization, issued a statement recently accusing India of using "her disputed occupation of Kashmir to carry out a deep conspiracy of turning Pakistan's agricultural lands into barren lands and economically annihilating her through building dams and water theft."
"If India continues with her water terrorism," it added, "Pakistan must keep open the option of using force."
Associated Press writers Asif Shahzad in Islamabad and Aijaz Hussain in Srinagar, India, contributed to this report.