(CNN) -- A Belgian military bomb squad investigated a suspicious vehicle outside the United States Embassy in Brussels, Belgium, on Wednesday, but found "nothing abnormal," officials said.
The building was "evacuated this afternoon as a precaution while Belgian authorities investigated a suspicious vehicle in the vicinity," the embassy said on Twitter.
The incident began when a police officer noticed that the car did not have the official plate required for parking by the diplomatic mission.
The officer checked and found something suspicious in the car, Brussels police spokeswoman Ilse Van de Keere said.
She refused to say what prompted the officer's concern.
Police later said they saw wires coming from the car, but there was "nothing abnormal to report."
Technicians are continuing to investigate the vehicle, and police are trying to determine who owns it and how it came to be parked near the embassy, they said.
The incident came just over a month after a fake bomb attached to a vehicle as part of a terrorism drill by the U.S. Embassy in Oslo, Norway, triggered a security alert at that embassy.
The U.S. Embassy had a rehearsal for a terrorism incident in mid-July, spokeswoman Siv Alsen of Norway's Police Security Service said.
They "used fake bombs, and one of those bombs was not removed" from the vehicle it was attached to, sparking the July 31 alert, Alsen said.
CNN's Alanne Orjoux, Andrew Carey and Jo Shelley contributed to this report.