A British Airways (BA) passenger jet landed short of the runway at Heathrow Airport Thursday.

The emergency escape chutes were used and passengers were led to safety, Sky News reported.

Three passengers are being treated for minor injuries, the report said.

Heathrow Airport's southern runway has been closed to incoming and outgoing flights.

The plane was BA flight 38 from Beijing to London, the report said.

Six ambulances were dispatched and emergency services remain at the scene.

"We can confirm that BA Flight 38 arriving from Beijing made an emergency landing at 12:42 p.m. (1242 GMT). Passengers have been evacuated," said an airport spokeswoman.

"The south runway is closed but the north runway is still operating," she added.

The plane landed just meters from a busy perimeter road, and the impact wrecked its undercarriage and caused extensive damage to both wings, Britain's Press Association reported.

"The plane's wheels collapsed, doors were flown open. It crashed into the runway, debris was flying everywhere, there was an enormous bang and it skidded sideways," eyewitness John Rowland was quoted by the BBC as saying.

"There were some sparks as the undercarriage or the bottom of the plane actually touched the runway -- certainly a huge amount of smoke coming up from that. And then the plane did come to a halt reasonably quickly," said Nick Gray, another eyewitness.

"It was incredibly efficient the speed that people got off the aircraft. I could see that the shoots were deployed very quickly and people were coming down on that. Then people were sent off to the nearby buildings which are probably only about 200 yards away from the plane," he said.

A spokeswoman for Scotland Yard police headquarters said there was no suggestion that terrorism was involved in the incident.

"There is nothing to suggest it is terror-related," she said.

The incident happened as British Prime Minister Gordon Brown was due to leave Heathrow for visit in China and India.

His flight, which was delayed a short while because of the incident, has left the Heathrow airport for China.