Belgian police evacuated hundreds of people Monday from the European Parliament to search a car for explosives, then arrested the owner -- a man clad in camouflage gear who had a gun and a chainsaw stashed in his vehicle.

Four European Parliament administrative buildings and its visitors' center in central Brussels were cleared as a precautionary measure while the car was searched, the assembly said in a statement.

Police found the firearm and chainsaw but no explosives, according to the public prosecutor's office.

The suspect, identified as a Slovak national born in 1982, was charged with "threatening an attack, possession of an illegal weapon and unauthorized possession of a firearm requiring a license."

The man "said that he wanted to meet the president of the parliament," a prosecutor's office statement said.

Parliament spokesman Jaume Duch Guillot said about 500 people were evacuated from the buildings.

Police gave the all-clear just before 1 p.m. Brussels time, and staff returned to their offices.

The suspect, who showed no signs of aggression throughout, declined to explain his behavior to police.

Belgium has been on high alert since the Jan. 7-9 Paris terror attacks and a series of police raids on suspected foreign fighters in Belgium and France last month. Soldiers now patrol major public buildings like the EU institutions.

The incident was one of three that mobilized police and blocked traffic in Brussels Monday.

In a separate alert, police detained a man who had been taking photos of the Brussels prosecutor's offices with his mobile phone and searched his van with an explosives sniffing dog.

Soldiers stationed at the building alerted police after the man fled when they tried to question him. He was later released without charge.

Belgian media also reported that police were called when a car was abandoned in a street near the U.S. embassy in Brussels, but the incident turned out to be a false alarm.