PARIS: Cyclists at the Tour de France will be under the watch of an unprecedented force of 23,000 police, including SWAT-like intervention squads, as the government tries to ensure security amid extremist threats.

France has been in a state of emergency since attacks on Paris in November killed 130 people, with soldiers guarding landmarks and religious sites. The emergency measures were extended last week to cover the European soccer championship next month and the Tour de France, which runs from July 2-24.

Interior Minister Bernard Cazeneuve met on Tuesday with Tour director Christian Prudhomme and afterward announced exceptional security measures.

Securing the Tour is unusually difficult, as crowds of fans gather informally on narrow mountain roads and city streets along thousands of kilometres around France. In past years, motorcyclists from the Republican Guard escorted the cyclists.

"Security is our priority - I might say the Tour de France organisers' No. 1 priority. Security of the participants, security of the fans along the roads," Prudhomme said.

In addition to the at least 23,000 police, Cazeneuve said, "We are currently assessing the need for a larger involvement of our security forces."

Cazeneuve said he asked the GIGN intervention squad "to follow the Tour de France through to the end of the event and stand ready to intervene at any moment if it proves necessary."

He promised similarly tough security around the Euro 2016, and acknowledged "a number of unfortunate mistakes" in security efforts at the Stade de France on Saturday that he vowed to fix.