The rescue operation to search for the 46 missing sailors of a South Korean ship that sank late Friday is still under Saturday, Seoul's Yonhap News Agency reported.

So far, 58 out of the 104 crew members aboard the 1,200-ton ship that sank off the west coast of the Korean Peninsula have been rescued, with two of them hospitalized for minor cerebral hemorrhage, the agency said. Earlier reports said 60 sailors have been rescued.

The cause for the sinking is unknown yet. President Lee Myung- bak demanded at the second emergency meeting with security officials earlier in the day a "quick and thorough" investigation and rescuing the missing by all means.

Lee also ordered related nations engaged in the six-party talks be informed of proper information about the incident while urging the government agencies to take measures to reassure the public, Presidential Office spokeswoman Kim Eun-hye said at a press briefing after the meeting.