MUZAFARABAD, Pakistan (AP) — Pakistan's military said Wednesday it shot down two Indian warplanes in the disputed region of Kashmir and captured a pilot, raising tensions between the nuclear-armed rivals to a level unseen in the last two decades.

India acknowledged one of its air force planes was "lost" in skirmishes with Pakistan and that its pilot was "missing in action" on a chaotic day, which also saw mortar shells fired by Indian troops from across the frontier dividing the two sectors of Kashmir kill six civilians and wound several others. A helicopter crash in the region also killed six Indian air force officials and a civilian on the ground.

Pakistan responded by shutting down its civilian airspace as Prime Minister Imran Khan called for negotiations with his Indian counterpart Narendra Modi, to ensure "better sense can prevail."

"Let's sit together to talk to find a solution," Khan said. There was no immediate reaction from Modi.

The aircraft went down Wednesday morning in Kashmir, a mountainous region claimed by both India and Pakistan since almost immediately after their creation in 1947. One of the downed planes crashed in Pakistan's part of Kashmir while the other went down in Indian-controlled section of the Himalayan region, Pakistan's army spokesman Maj. Gen. Asif Ghafoor said.

Pakistani troops on the ground captured an Indian pilot, he later said, after earlier saying it captured two. He did not explain what caused the confusion.