At least 185 bodies have been recovered and 389 survivors rescued from the waters where the 35-year-old ferry, Al Salam 98, sank on its journey to Safaga in Egypt from Duba in northwest Saudi Arabia, an official said.
The ferry was carrying 1272 passengers, mainly Egyptians, and 100 crew when it lost contact with the shore at about 10pm (2000 GMT) on Thursday.
Relatives of victims of the ferry disaster threw stones at Egyptian riot police as their grief and frustration turned to anger.
At the port of Safaga relatives clashed with police who retaliated by using tear gas and sticks.
Lack of information has left families without answers as they continue to wait for a second day without word of their relatives.
General Mahfuz Taha, head of the Red Sea Ports Authority, said rescue efforts would continue, but a source close to the operations said: "There aren't expected to be many survivors, because it's been so long since the ship went down."
Some of the survivors, recovering in an Egyptian hospital, said they spent up to 20 hours in rubber dinghies and holding on to life buoys waiting to be rescued.
Rifat Said, 34, said he picked up a life buoy from the ship before jumping in the water. "Then I found a big rubber dinghy," he said. "There were 20 people in it," he said.
Ashraf Said Muhammad said he clung to a ring for 16 hours. "I had thought it was the end," he said.
The ferry, which the survivors said had thick smoke coming from it before it sank, had a complement of 100 crew when it lost contact with the shore at about 10pm (2000 GMT) on Thursday.
"It just went on to its side and within five minutes it had sunk"
Rifat Said, a survivor
The survivors said the ferry had thick smoke coming from it before it sank. They said that it began listing to one side shortly after leaving Duba port in Saudi Arabia, but sailed on for two hours, before listing further and then rapidly sinking.
"It just went on to its side and within five minutes it had sunk," Saeed said.
An official from the company that owned the ferry said coastal stations had not received a distress call; but MENA, the Egyptian state news agency, said another ship picked up a message from the ferry's captain saying his vessel was in danger of sinking.
Relatives of passengers gathered at the gates of the port where the ferry should have arrived at 2am (midnight GMT) on Friday.
One man, Gadir Muhammad, said: "They are not telling us anything. Where are the corpses? Where are they taking the survivors?"
Officials and experts initially said poor weather was likely to have caused the sinking, but Egypt's presidential spokesman suggested safety problems.
"The speed with which the ship sank and the lack of sufficient lifeboats indicate there was some deficiency," Sulayman Awad told Egyptian television.
Majority of the passengers on board
A shipping company official said the Saudi authorities had confirmed that everything was in order when the ship sailed.
An official at al-Salam Maritime Transport Company, which owned the Panamanian-registered ferry, said it remained unclear what had happened to the ship, which was built in Italy in 1970 and moved to the Egyptian company in 1998.
None of the officials said there was any indication that the sinking was the result of an attack on the ferry.
One expert said the ship had a loading mechanism for vehicles that could have let in water. Richard Clayton, news editor of the shipping weekly Fairplay, said: "If these doors are open for any reason, then you've had it."
MENA said the passenger list included 1158 Egyptians, as well as about a hundred others, including Saudis, Syrians, and a Canadian.
A sister ship of the sunken ferry, the Al Salam 95, sank in the Red Sea in October after a collision with a Cypriot commercial vessel. Almost all the passengers were saved.