Police suspect a bomb caused an explosion that killed a man driving in rush hour traffic in central Berlin.

The man's car was blown up in a busy street in the western district of Charlottenburg about 8.00am local time.

"Our investigators are working on the assumption that it was an explosive device that caused this," said Carsten Mueller, deputy chief spokesman for Berlin police.

"[The] explosion occurred inside or on the vehicle".

Nobody else was injured in the blast despite heavy traffic at the time of the blast, Mr Mueller said.

Image via @polizeiberlin on Twitter

The scene was sealed off while bomb experts checked the vehicle but no further explosives were found.

People were told to close their windows and stay off their balconies.

Police posted an image on Twitter of the wreckage of the car - a silver Volkswagen Passat - on the wide road.

Its windows were blown out and front end smashed in. The vehicle was heading towards the city centre when it exploded.

Detectives were still trying to determine the dead man's identity, Mr Mueller said.