The latest update comes from Reuters:
UPDATE 2-S.Korean navy ship sinking, North suspected-media
SEOUL, March 26 (Reuters) - Several South Korean sailors were killed and one of its naval ships with more than 100 aboard was sinking on Friday after possibly being hit by a North Korean torpedo, South Korean media reported.
A South Korean vessel fired at an unidentified vessel towards the north and the South's presidential Blue House was holding an emergency security meeting, Yonhap news agency said.
South Korea's YTN TV network said the government was investigating whether the sinking was due to a torpedo attack by the North.
The network also quoted a government source saying it was unclear yet whether the incident was related to North Korea.
"We are currently focusing on rescuing people," the source said.
The incident took place near a disputed Yellow Sea maritime border off the west coast of the peninsula that was the scene of two deadly naval fights between the rival Koreas in the past decade.
Local media reports said at least 59 South Korean sailors survived the attack and an unknown number appeared to have been killed or were missing. A rescue operation was under way.
Navies from the rival Koreas exchanged gunfire for the first time in seven years in the Yellow Sea waters in November, damaging vessels on both sides.