Brussels - Prosecutors say a man has been charged with terror offences including attempted murder after he was arrested driving at high speed into a crowded shopping area in the Belgian port city of Antwerp.However, a source close to the investigations could not confirm if it was a terrorist attack and said the driver made little sense during interrogation. Other sources said the charges could be interpreted as a "precautionary measure" in order to keep the suspect in detention.Killed fourThe suspect, a 39-year-old Tunisian identified as Mohamed R, was charged with "an attempt to murder in a terrorist manner; an attempt to hit and wound in a terrorist manner and arms infractions," the federal prosecutor's office said in a statement. The authorities said they found a rifle and bladed weapons in the car after they arrested the suspect on Thursday.The incident came a day after a similar attack on the British parliament killed four people plus the attacker. Wednesday was also the first anniversary of the Brussels suicide bombings in which 32 people died. Mohamed R drove at high speed through the busy Meir shopping area in Antwerp, forcing people to jump out of the way, authorities said.He also ignored an initial order to stop by soldiers.The Antwerp incident put Europe further on edge after the London attack and the incident at Paris's Orly airport last Saturday when a man was shot dead after grabbing a soldier's rifle.Investigators said the man in Antwerp was clearly "under the influence of something" but it was not clear what substance.He was not in a state to be questioned by police until Friday, a source said.Boot of carThe source said: "Recently, he lived in his car - given the mess we found in there - between Belgium and the Netherlands where he was also checked by police".Interrogated by French police, a friend of the suspect's said the weapon in the boot of the car had been there for a long time and did not work. Belgium suffered a further shock in August when a machete-wielding man shouting "Allahu akbar" (God is greatest) attacked two policewomen in the industrial town of Charleroi, before being shot dead.