A passenger ship carrying 462 on board was sinking in waters off South Korea's southwest coast on Wednesday morning, April 16, 2014. [Photo: Imagine China]

A passenger ship with 462 people aboard, mostly high school students, sank in waters off South Korea's southwest coast Wednesday morning, leaving at least four people dead and 284 others missing, local media reported citing the central disaster and safety countermeasures headquarters.

Four people, including a 22-year-old female crew member and three high school students, were found dead as of 9 p.m. local time, with 174 people confirmed rescued and 284 others still missing.

The death toll continued to rise as hundreds of passengers were still missing around nine hours after the ship sank deep into the waters. The number of death was feared to surge as people in the waters can endure hypothermia only for three hours.

The 6,825-ton passenger ship "SEWOL" was capsized and sank down into waters off the Jindo Island, just off the southwest corner of the Korean Peninsula, at around 11:30 a.m. local time Wednesday.

The ship sent out a distress signal at about 8:52 a.m. and had floated in the waters for some two and a half hours with its body being on the careen.

Figures by the headquarters showed the ferry carried 30 crew members and 432 passengers, including 325 high school students and 15 teachers who had been on the way for a school journey.

The ship departed from South Korea's western port city of Incheon Tuesday night, heading for the southern resort island of Jeju.

Among the 174 people confirmed rescued, 78 were high school students. A total of 55 people were transferred to nearby hospitals, but they had minor injuries.

The Coast Guard suspended searching operations into the hull at around 8 p.m. as the faster-than-expected tidal currents and muddy visibility blocked divers from entering into the ship's body.

The searching operations into the body will be resumed at around 1 a.m. Thursday. Around 180 divers were sent to the scene for search and rescue operations during the night time.

Most of those missing were estimated to be trapped inside the sunken vessel, the Coast Guard said.

Other ships and helicopters were continuing to search waters near the scene. After receiving the distress signal, the South Korean authorities dispatched 72 rescue ships and scrambled 14 helicopters for rescue operations.

But, salvage operations will start as early as Friday morning as it will take time for three cranes to arrive at the scene.

The vessel was believed to run aground in the waters as some rescued passengers said the ship began leaning to the port side after making a thumping sound on the bow.

The ferry veered off the pre-arranged route as it departed some two and a half hours later than scheduled due to a thick fog.

There was no Chinese passenger on board the vessel, according to the Chinese Embassy in South Korea.