ANKARA, September 15, 2008 (AFP) - Rescuers saved some 100 people from a ferry that sank off the Turkish coast and scoured the sea Monday for at least four missing passengers after finding one body, officials said.

The 118-metre (390-feet) long ferry, loaded with 73 trucks and two cars, capsized late Sunday, shortly after setting out from Bandirma, on the southern shore of the Marmara Sea in the country's northwest, for Istanbul.

It was not immediately clear why the ferry sank, but officials and survivors said the vessel began listing to the left as it pulled out of the port.

There were 106 people -- including 27 crew -- on board the vessel, and 101 of them had been pulled out of the water, Selahattin Hatipoglu, the governor of Balikesir province, where Bandirma is located, told the Anatolia news agency.

One passenger, a truck driver who did not know how to swim, died and four other passengers remained unaccounted for, the governor said.

The deputy head of Turkey's maritime agency, Mehmet Solgun, earlier offered little hope of finding the four missing people alive.

'The fact that we have been unable to reach these four people gives strength to the possibility that they are still on board the vessel,' Solgun said.

A frigate, a mine sweeper, four coast guard vessels and two helicopters were taking part in the search along with 21 divers, the Turkish navy said in a statement.

The wreckage was some 20 to 30 meters (65 to 100 feet) underwater, Hatipoglu said.

An investigation was underway into the cause of the accident and police were questioning the ferry captain and two assistants, the governor added.

Some survivors have blamed the accident on the crew, claiming the ferry was overloaded.

But the owner of the ill-fated vessel, Marmara N maritime company, denied the accusations, saying the ship was carrying less than half of its capacity.

'The ferry, which can carry 100 trucks and a total of 5,273 tonnes, had set out with 75 vehicles that were carrying 2,400 tonnes,' said the statement carried by Anatolia.