SEOUL, South Korea (AP) _ A South Korean soldier missing for two weeks was found dead on a mountain slope today, apparently killed by North Korean infiltrators from a submarine that ran aground in September.

The body of Pfc. Pyo Chong-wook, 22, was discovered a day after South Korean troops shot and killed two North Korean agents, one of whom was wearing Pyo's uniform.

Pyo had been strangled several miles from where the two communist agents were killed in a gun battle, Defense Ministry officials said.

He was the 13th South Korean killed since 26 North Koreans came ashore from a submarine stranded on the east coast Sept. 18.

So far, 24 of the North Korean intruders have been killed or found dead. One has been captured and another is still missing.

Meanwhile, Defense Minister Kim Dong-jin promised to punish commanders found guilty of negligence, including a general whose division failed to detect the stranded submarine. It was spotted a few yards off the coast by a taxi driver.

The submarine incursion has significantly heightened tension between the two Koreas, high since the 1945 division of their peninsula into the communist North and the capitalist South.

South Korea says the submarine was sent to deliver spies, while North Korea claims it drifted across the border after developing engine trouble during a training mission.