AMSTERDAM, Netherlands (AP) _ Exhausted passengers from a Dutch flight hijacked to Germany returned to Amsterdam early Monday, and some said they hadn't been aware that a hijacking was going on.

The 11-hour hijacking ended early Monday when police in Duesseldorf, Germany stormed the plane after the last of the 138 hostages slipped out unnotice. The hijacker was arrested, and no one was hurt, police said.

Most of the passengers from the flight traveling from Tunis, Tunisia, to Amsterdam, arrived at Amsterdam's Schiphol Airport early Monday aboard a special flight.

Many said they never knew their plane had been hijacked.

The captain announced to the passengers that there was a problem in the cockpit, and ''it was not a technical problem,'' said KLM spokesman Ron Wunderink, adding that the wording was intended as a signal that a hijacking was in progress.

''We were told there was a person on board who wanted to go to New York and not to Amsterdam,'' said passenger Iver Osterveld. ''The word hijacking wasn't used ... Even the stewardesses didn't know what was going on.''

A Tunisian passenger, who declined to give his name, said a flight attendant came into the cabin and got a passenger to translate for the hijacker, who spoke only Arabic.

He was not aware of the hijacking until after the plane landed in Dusseldorf.

Osterveld criticized security in Tunis.

''It would have been easy to get anything on board,'' he said. ''There was no good security in Tunis. No one was looking at the screen as the (carry-on) baggage went through.''

But KLM spokesman Ron Wunderink said in an interview that all passengers and all luggage were checked at the Tunis airport.