A Boeing airliner carrying 231 people from the U.S. landed on its belly in Warsaw on Tuesday after its landing gear failed to open, triggering sparks and small fires. No one was injured.

The pilots of the Polish LOT airlines flight from Newark, New Jersey, discovered a problem with the chassis ahead of touching ground. They circled the 767 above the airport for about one hour before descending without the landing wheels, said Przemyslaw Przybylski, a spokesman for the Warsaw airport.

LOT spokesman Leszek Chorzewski said the plane landed with nearly empty fuel tanks after dumping fuel in preparation for the emergency landing.

A fire brigade laid out special flame retardant foam for the plane to land on. On landing, sparks flew from the engine and small fires erupted under the plane but were immediately put out by firefighters.

Passengers could be seen evacuating the plane. They were then taken to a medical center to be examined by doctors, Przybylski said.

"There was no panic among the passengers. The cabin crew prepared them for the emergency landing well," LOT airlines president, Marcin Pirog, told reporters.

Pirog said Captain Tadeusz Wrona and co-pilot Jerzy Szwartz carried out a "perfect emergency landing," which prevented anyone from being injured.

"It is the first time a LOT plane had to land without the landing gear out," Pirog said, adding that such landings do not always end well.

The airport has been closed until 8 a.m. on Wednesday. Flights which had been scheduled to land in Warsaw have been diverted to Lodz, Gdansk and Krakow.

Poland's President Bronislaw Komorowski congratulated and thanked the crew for their successful landing.