CALGARY — An aircraft has crashed into Beijing's tallest building, and authorities have still given no information about the incident. Reported by Reuters, witnesses told the news outlet about the crash which occurred on Friday evening Chinese Standard Time, as police closed off roads around the 108-storey skyscraper in Beijing's central business district. The building is known as CITIC Tower or China Zu, and is the headquarters of the state-owned conglomerate CITIC Group.Reportedly, there was a heavy police presence on site after the incident, while one approach road was closed..Two glass panels on a high floor were damaged, and there has been no official response yet.One courier told Reuters he had been standing outside near the building, and he rushed over after he heard a loud crash, after an aircraft the size of a car hit it."It was so loud — louder than fireworks," he recalled.The courier said he had taken a video of the aircraft sticking out of the building but had deleted it in fear that the police might catch him..Police had prevented onlookers from taking video or pictures, and asked others to delete those they had taken while ushering people away from the building.Social media posts made about the building and the aircraft crash were quickly removed from Chinese social media.An office worker in a nearby office building says she saw a blue tarp covering a large object on the road at the side of the building, roughly the size of a VW Beetle from her office window only 45 or so minutes after the crash."I was on my way down to dinner when someone said a plane had crashed into the next building. So we went to look out the window and saw police cars, ambulances and the blue tarp on the road," she said..It is unknown whether the crash was accidental or deliberate, as airspace in Beijing's downtown is heavily restricted.