JINDO, South Korea (CNN) — Divers retrieved yet more bodies from the sunken South Korean ferry Sewol on Wednesday as hopes of finding survivors faded on news that rescuers haven't found any air pockets inside the ship.
South Korean officials have continued to call their operation a search and rescue mission. But rescuers sent into the cold, murky waters of the Yellow Sea haven't found a single survivor since 174 people were rescued the day the ship sank one week ago.
All rescuers have found are bodies -- 156 at last count Wednesday night. Another 146 remain missing, authorities said.
Many of the bodies pulled from the ferry have come from bedrooms on the capsized ship's fourth deck, according to Ko Myung-suk, a spokesman for the joint task force coordinating the search.
Divers had expected to find passengers inside the third-floor cafeteria but failed to find any, the South Korean coast guard said.
No air pockets have been found on either deck, authorities said.
Divers still have many rooms to search, authorities said.
Grief over the sinking has spread across the Korean Peninsula. Even South Korea's nemesis, North Korea, sent condolences Wednesday.
More than two-thirds of those on board the ferry were students from Danwon High School in Ansan, an hour's drive south of Seoul. They were on a field trip to a popular vacation island.
On Wednesday, some of their faces stared out from photos amid a huge bank of white flowers at a basketball area in Ansan that has been converted into a temporary memorial.
A permanent memorial is being planned for a park in Ansan.
Hundreds of people filed through the memorial Wednesday, passing about 50 large wreaths on their way to the wall of flowers and pictures.
Somber music played as visitors, including friends and relatives, passed quietly among the tributes. Some wept.
One man, from Seoul, has no ties to the school but came to grieve for the young lives lost.
"I have a daughter," the man told CNN's Nic Robertson. "I think of her alone in black waters. It's just so terrible. I'm angry that I couldn't do anything. So helpless."
The disaster has taken a devastating toll on the high school, where classes are due to resume Thursday.
The school is missing most of its sophomores and a vice principal who was rescued from the ferry but found dead two days after the sinking. He'd apparently hanged himself from a tree.
Lee Seung-min, 17, said one of her closest girlfriends is among the missing. She said she still holds out hope that her friend will return despite the increasingly slim chances of finding survivors.
Before the field trip, the two girls had talked about what universities they might attend, she said.
Crew members arrested
Investigators, meanwhile, are trying to establish what happened to make the ship list before finally capsizing and sinking into the ocean.
Prosecutors said Wednesday that investigators had searched the offices of the ferry operator, Chonghaejin Marine. The home of the company's owner also was searched, prosecutors said.
The captain, Lee Joon-seok, and 10 crew members have been arrested. Some of them are facing criminal charges.
Questions remain over the decisions Lee and some of his crew made as the crisis unfolded. They have been criticized for not getting more people off the ferry sooner, although the captain has said he was worried about the cold water, strong currents and lack of rescue vessels.
They have also drawn public anger for leaving the ship while many passengers remained stuck on board.
Adding to the perception of chaos on board the sinking vessel, it emerged Tuesday that the first distress call from the ferry came not from the crew, but from a student using a cell phone to contact emergency services from aboard the sinking ship.
CNN's Michael Pearson reported and wrote from Atlanta. CNN's Steven Jiang reported from Jindo, and Andrew Stevens reported from Ansan. CNN's Jethro Mullen, K.J. Kwon, Kyung Lah, Tim Schwarz, Larry Register and Judy Kwon also contributed to this report.
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