More than 24 hours after the Costa Concordia stormed the Italian coast, three survivors were found on the surviving cruise ship.
Rescuers are trying to reach a third survivor, hours after the honeymoon, the South Korean couple was rescued.
So far, three people have been confirmed dead and about 40 are unaccounted for.
Francesco Shetino, the Italian captain of the Costa Concordia, has been arrested on suspicion of multiple murders. Prosecutors say he left the ship before the evacuation was complete.
The first officer, Ciro Ambrosio, was also detained.
The ship’s operator, Costa Crochiere, said the ship was following its regular course when it hit a sunken rock.
In a television interview, the ship’s captain, Francesco Shetino, said the rock was not marked on any nautical chart.
Police are investigating why the incident took place in calm conditions.
The South Korean couple was located after rescuers heard voices from a cabin on two decks of the half-sunken ship late Saturday. They were reached a few hours later.
The newlyweds, both 29 years old, were both in good health when they were brought ashore.
Later Sunday morning, rescuers found and spoke with the third man found inside the ship. Officials say he is a senior Italian crew member and believe he has a serious leg injury.
Two divers smashed a ship’s window, trying to reach someone inside.
Two French passengers and a member of the Peruvian crew were killed and 30 others were injured, two seriously.
Divers continue to search for the ship, which lies on the side near the Tuscan island of Giglio.
Costa Cruises President Gianni Onorato said the company’s main task now is to help survivors and repatriate them.
He said it was difficult to determine what had happened, but that the ship had been eclipsed after hitting a “large rock”.
Gianni Onorato added: “We will work in full transparency with the Italian authorities to understand the causes of the disaster.”
He said the normal evacuation of a lifeboat had become “almost impossible” because the ship had counted so quickly.
Francesco Shetino, the 52-year-old captain, worked on the Costa Cruise for 11 years.
The prosecutor general in the city of Grosseto told reporters that Captain Francesco Sketino “was very unevenly close to Giglio,” the Italian news agency Ansa reported.
Italian, German, French and British citizens were among the 3,200 passengers on board. There were also 1,000 crew members.
Coast Guard Captain Cosimo Nicastro told Italian television that divers had conducted an in-depth search of the waters near the ship and found no other bodies.
On Saturday, the survivors were taken to Porta San Stefano, about 25 km (15 miles) from the mainland.
Many arrived there still wrapped in blankets, and some were obviously shaken by the experience.
Passenger Luciano Castro told Ansa: “We heard a loud noise while we were having dinner, as if the ship’s keel had hit something.”
“The ship began to draw water through the hole and began to tilt.”
Some passengers told the that the crew had not given instructions on how to evacuate the ship.
Several passengers compare the incident to the movie “Titanic” about the sinking of the giant ocean liner in April 1912, which took more than 1,500 lives.