A small plane appeared to have crashed into Beijing's tallest building on Friday, with witnesses reporting plane debris at the skyscraper's base and AFP journalists seeing a hole in the building's upper floors.

Video footage taken by a witness from a nearby building showed fire trucks blasting water at small flames on an outcropping near ground at the 528-metre (1,732-foot) CITIC Tower, as well as on the pavement. 

The images also showed what appeared to be part of a small plane on the ground beside the building.  

Video on Chinese social media that appeared to be of the same skyscraper showed debris falling from the building. AFP could not immediately verify this clip.

AFP journalists at the scene saw a hole in the windows of one of the upper floors of the skyscraper, which is located near the CCTV public television headquarters in the east of the Chinese capital.

Police and ambulances swarmed the area, with officers blocking people from taking photos.

Police declined an AFP request for comment.

"I don't know why the plane would fly in here. It really is quite strange," one witness, a finance worker, told AFP on the condition of anonymity.

A man who worked inside the CITIC building told AFP: "I saw debris on my way out. It looked like part of a plane."  

Dozens of uniformed cleaners gathered near the police cordon on Friday evening. 

One woman told AFP she had been told to evacuate the building via the stairs and not to use the lifts. 

"I ran down dozens of floors in a hurry," she said. 

Two men who appeared to be from the building's property management team told the cleaners to go home. 

"No one can get in now," one of the men said.

'Shouldn't happen'

A middle-aged woman who was staring at the building from the street said she was shocked by the incident. 

"This kind of thing wouldn't happen in Beijing. This is Beijing... It's pretty common abroad, but in China, it shouldn't happen," she told AFP.

"I was very shocked." 

A student at the scene told AFP he rushed to the building as soon as information about the crash was shared in an aviation enthusiast social media group. 

Images and posts online were being rapidly deleted, he added. 

The CITIC Tower, which has 108 floors above ground and seven below, is able to accommodate 12,000 office workers.

China imposes strict restrictions over its airspace, particularly around Beijing's urban area, citing public security for the new rules.

In April, China announced it was banning the sale of drones in Beijing and would require users to apply for permission for all flights in the capital.

That same month, China banned civil aviation for 40 days from a large airspace off Shanghai without specifying the reasons, according to a notice to aviators published by the US Federal Aviation Administration (FAA).