French police raise security, search for motive after 2 weekend attacks

This photo provided Monday, Dec. 22, 2014 by local newspaper Le Bien Public shows rescue workers tending at victims after a driver deliberately slammed into passersby in several spots in Dijon, central France, Sunday Dec. 21, 2014. French police are raising security after an attack on officers in central France, and the country’s top security official is arriving in the city where a driver ran down 11 pedestrians. (AP Photo/Christian Guileminot; Le Bien Public) (The Associated Press)

A female police officer stands by the van that crashed into a French Christmas market in Nantes, western France, Monday, Dec. 22, 2014. French authorities urged calm after a series of attacks across the country left dozens of people injured, and said there was no evidence the attacks were connected by any terrorist motive. In the latest incident, 11 people were injured after a driver crashed his van into a crowded Christmas market in western France Monday evening. The driver then stabbed himself several times and is among five people hospitalized in serious condition, authorities said. (AP Photo/Laetitia Notarianni) (The Associated Press)

PARIS – French police are boosting security after an attack on officers in central France, and the country's top security official is visiting the city where a driver ran down 11 pedestrians.

The visit of Interior Minister Bernard Cazeneuve on Monday was an indication of the government's heightened concerns days after Islamic extremists renewed calls for individuals to attack in the West.

Counter-terrorist police are investigating Saturday's knife attack on police in a suburb of Tours, which left two officers seriously injured and the attacker dead. On Sunday, a driver with a history of psychiatric problems rampaged through Dijon. Cazeneuve was visiting those injured in the attack.

French-speaking Islamic State militants have called for attacks in the West, most recently in a video posted on jihadi forums on Friday.