HANOI, Vietnam - A fugitive mouse delayed the departure of a Japan-bound airliner for more than four hours Sunday as technicians hunted down the potential threat, airline officials said.

A passenger spotted the white mouse running on the floor of the plane on an initial leg of the Vietnam Airlines flight, prompting a hunt by about a dozen technicians worried that it could chew through a vital wire.

The mouse was found in a food storage area and the Boeing 777 was cleared for takeoff, said Tran Tien Dung, head of the airline's air safety department.

"This is the first time we experienced something like this," airline spokesman Nguyen Chan said.

Chan said Vietnamese aviation authorities suspect that a passenger brought the mouse on board in hand luggage.

Dung said the airline will caution passengers and increase baggage checks to make sure that no live animals are brought on board.

The mouse was killed, Dung said.