PARIS –  France’s high-speed TGV rail service is expected to return to normal by Monday, the government and railway operator said, a day after sabotaged signal stations and cables caused widespread chaos hours before the Paris Olympics opened.

“The complete return to normal is expected for Monday,” Transport Minister Patrice Vergriete told journalists on Saturday. Vergriete said security on the network was strengthened, with 250 personnel and 50 surveillance drones deployed along with police helicopters.

The attacks raised security concerns as the French capital hosts the world’s largest sporting event. While an investigation is under way, the authorities have not identified the perpetrators.  “Who is responsible? Either it’s from within, or it’s been ordered from abroad, it’s too early to say,” Interior Minister Gerald Darmanin told France 2 television.

There has been no immediate claim of responsibility for the widespread disruption. Railway company SNCF said it had made progress in partially restoring services. But there were widespread delays and cancellations.

SNCF said its agents worked through the night in adverse weather conditions to improve traffic from the north, east and west to Paris. As of Saturday morning, normal service had resumed on the eastern high-speed line.  “On the north, Brittany and southwest high-speed lines, seven out of 10 trains on average will run with delays of one to two hours,” SNCF said. (Al Jazeera) …[+]