The figures will probably always vary wildly depending on which side you're listening to.
Here's what Wiki says:
"Total civilians killed/wounded: 2.5 million (est.)[9]
South Korea: 990,968
373,599 killed[9]
229,625 wounded[9]
387,744 abducted/missing[9]
North Korea: 1,550,000 (est.)"
Korean War - Wikipedia, the free encyclopedia
Other accounts place the population of North Korea at 9 million when the war began with about six million survivors in 1953. Whatever the actual numbers, hundreds of thousands of North Korean civilians died primarily from US air power, and they haven't forgotten or forgiven.