PRAGUE — Officials in the Czech Republic say a helicopter has crashed in a western city, killing all four people onboard.

Regional rescue service spokesman Martin Brejcha says that the crash has occurred in Plzen, about 100 kilometers (60 miles) southwest of Prague. The victims haven't been identified.

Local firefighting spokesman Petr Poncar says the helicopter crashed on the roof of an empty factory hall in the industrial zone of Plzen on Wednesday afternoon. He says that the crash didn't spark a fire and no one else has been injured.

The CTK news agency reported that the aircraft was a small Robinson helicopter.