LONDON -- A ferry bound for Amsterdam was forced to return to England Sunday following a fire which sent passengers to the outer deck in the middle of the night and prompted rescue services to scramble lifeboats and helicopters.

The ferry, carrying 946 passengers to Holland, had sailed just 50 kilometres in the North Sea when the fire broke out at about 11 p.m. Saturday. It was quickly contained, but two crew members and four passengers were taken off the ferry for treatment for smoke inhalation before it returned to Newcastle, in northern England. Twenty-three other people were treated on board for smoke-related injuries.

Local police said a 26-year-old passenger has been arrested on suspicion of starting the blaze. Another, 28, has been arrested on suspicion of fighting. Neither man was named, in line with British practice.

The circumstances surrounding the fire -- which started in one of the ship's cabins -- remain unexplained, although the evacuation of passengers to the outer deck of the ship was generally described as calm. One eyewitness told the BBC some passengers jokingly began singing the theme song from "Titanic."

Another passenger, 28-year-old Steven Basford, said people were mostly well-behaved, although he said two men got into a fight.

"Obviously people had had a lot to drink," Basford said. "It's a bit of a party boat."

The boat is due to remain in dock for another day while authorities inspect the damage.