The coordinated rail attacks that disrupted train travel in France on three high-speed lines Friday morning occurred despite intensive security precautions put into effect leading up to the Olympics, which officially begin Friday night.
Not only have police and soldiers poured into Paris over the past week to sweep and secure the Olympic sites and the center of the city along the Seine, where the opening ceremony is scheduled to take place, but they visited the homes of people they considered potential threats and imposed what amounts to house arrest on 155 of them.
The dragnet yielded some results. In central France, a man of Chechen origin was charged in May with the planning of an attack outside an Olympic soccer match in Saint-Étienne. Another man, a neo-Nazi sympathizer living in the Alsace region, was sentenced to two years in prison for publishing an explosives recipe online and for making threats.
This week, a 40-year-old Russian man was charged with working at the behest of a foreign power to “provoke hostilities” in France intending to destabilize the Olympic Games.
Police also did background checks on around one million people involved in the games, including security guards, stadium workers and volunteers, France’s interior minister, Gérald Darmanin, said earlier this week.
Of those, about 5,000 people were rejected because of their criminal records or flagged for “radicalization.”
Around 1,000 of them were suspected of foreign espionage, Mr. Darmanin said.
“These people, we thought it wouldn’t be a good thing for them to work in stadiums or accompany volunteers or the teams,” he said.