PARIS -- French officials called for vigilance but warned against jumping to conclusions Monday after a pair of weekend attacks -- one in which a driver ran down 13 bystanders, and another in which a recent convert to Islam knifed police officers.

The driver, who had a history of psychological problems, was arrested following the attack in the city Dijon in eastern France, while the assailant who stabbed the officers outside the city of Tours was shot to death by police. None of the victims died.

The prosecutor in Dijon said the driver behind the attack in that city has a long history of severe mental illness and no links to terrorism.

The man, who is 40, has admitted his role in the attack, said prosecutor Marie-Christine Tarrare. She said he had been hospitalized 157 times for psychiatric problems since 2001, most recently this fall.

She said the man, the French-born son of North African immigrants, acted alone and had no religious motivations, but rather was upset at the treatment of Chechen children.

He shouted 'God is great' to give himself courage to act, and not out of religious belief, Tarrare said.

The suspect was arrested. Eight people remain hospitalized Monday.

French Interior Minister Bernard Cazeneuve visited Dijon Monday, an indication of the government's heightened concerns days after Islamic extremists renewed calls for individuals to strike in the West.

Counter-terrorist police are investigating the attack Saturday on police in a suburb of Tours, which left two officers seriously injured and a third with light injuries.

Paris prosecutor Francois Molins said the attacker, who was killed by police, was a 20-year-old from Burundi named Bertrand. Police believe he'd been drawn to radical Islam several years ago by his 19-year-old brother Brice, who's been detained for questioning by police in Burundi, Molins said.