SEOUL — North and South Korean navy ships exchanged fire Saturday morning in the Yellow Sea off the Korean peninsula's demilitarized zone, leaving four South Korean soldiers dead and 22 others injured, according to the Defense Ministry.

It was the first major exchange of fire between the two Koreas in the Yellow Sea since June 1999.

According to South Korea's Joint Chiefs of Staff, two North Korean ships fired on South Korean vessels when the South Korean side warned them that they had intruded into the South's territorial waters around 10:30 a.m. The South Korean ships returned fire, but the two North Korean vessels returned to their territorial waters about 30 minutes later.

"The North Korean ships, in flames and apparently greatly damaged, were seen being towed back to port," the Yonhap News Agency reported, adding the South Korean vessels also sustained damage.

North Korean patrol boats have entered the South's territorial waters about 10 times since the start of this year, but this is the first case in which fire was exchanged. The area is near the inter-Korean maritime border called the Northern Limit Line.

The clash prompted the United Nations Command, a monitroing force established in 1953, to call for military talks with North Korea at the truce village of Panmunjom.

President Kim Dae Jung called an emergency meeting of his National Security Council to discuss the situation, the presidential Blue House announced. "This is a military provocative act of raising tension on the Korean Peninsula, and we can never tolerate this," Kim told a security meeting after the naval clash.

North Korea, for its part, blamed the South for provocation. The North's Korean Central News Agency said South Korea committed "such a grave provocation as firing bullets and shells at patrol boats of North Korea's navy on routine coastal guard duty."