A small aircraft appeared to have crashed into the 109-storey CITIC Tower, the tallest building in Beijing, on Friday afternoon, triggering an emergency response in the Chinese capital.

Dramatic videos shared on social media showed debris falling from the skyscraper, also known as China Zun, while what appeared to be the aircraft’s tail section and a damaged taxicab were seen on the ground.

Witnesses reported that occupants of the building were evacuated shortly after the incident as fire trucks, police vehicles and ambulances were deployed to the scene.

A CNN journalist at the location observed evacuees gathering outside the entrance of the high-rise while emergency personnel cordoned off the area.

Authorities had yet to release an official statement on the incident as of press time. CNN said it had contacted relevant authorities and a number linked to the aircraft’s registered owner for further information.

Images circulating online showing the aircraft’s registration number suggested it was a domestically manufactured Sunward SA60L Aurora light sport aircraft owned by a local general aviation company.

Unverified flight tracking data shared online also appeared to indicate the aircraft deviated significantly from its expected flight path before the crash.

The incident occurred despite Beijing’s stringent airspace controls. Since May 1, the Chinese capital has operated under strict regulations that effectively prohibit the purchase, rental and operation of drones without prior government approval.

The cause of the crash, the number of casualties and the extent of the damage were not immediately known as investigations continued.