A light aircraft has crashed close to the German parliament and Chancellor Gerhard Schroeder's office.
The plane was flying low and slow, witnesses said
The single-engine plane crashed on the lawn of the Reichstag shortly before 2100 (1900 GMT), the fire service said.
The cause of the crash, in which the pilot died, is unclear. Berlin police says they do not believe the crash is connected to terrorism.
"Nothing, absolutely nothing indicates a terror background," said Interior Minister Eckhardt Koerting.
"It appears at this point that it may have been some sort of accident or a case of suicide," Mr Koertig told reporters.
Since the London bombings, the German authorities have been on high alert, with security stepped up at public buildings across the country, says the BBC's Tristana Moore in Berlin.
A witness said the plane had been flying low and slow between the Reichstag building and an adjoining block of offices.
"I got the feeling he (had) to do something: climb or land," Alfred Koser told the Associated Press new agency.
"The plane flew right over me. I thought it was some kind of show."
Another witness said the plane was flying upside down and the pilot was trying to land.
No-one on the ground is reported to have been injured.
According to initial reports, the pilot did not have any explosives on board the aircraft.