France is “on alert” for further sabotage attacks after the coordinated assaults on the railway network on Friday that caused chaos hours before the Paris Olympic opening ceremony.
The SNCF rail network is likely to be subject to delays all weekend after the attack on Friday which could have been left-wing activists or Russians, the Telegraph has reported.
The opening ceremony went ahead as planned with a huge display on the river Seine and the first proper day of sport is set to get underway on Saturday morning.
But organisers are wary that further attacks could be attempted over the next fortnight.
Patrice Vergriete, the French transport minister, said: “Today we are on alert, so obviously we have mobilised all security forces, as well as drones, so today we have greatly increased our vigilance.”
The Telegraph quoted AFP news agency as saying a French intelligence source had identified the hard left as a possible source of the attacks but this has not been confirmed by Paris officials. The same is true for the Russian identified cause.
No group has claimed responsibility for the attacks.
Gerald Darmanin, the French interior minister, said there had been as many as four extra attacks foiled by the Parisian security and that the threat level remained “high”.
Trains are now running but many have been subject to changes or cancellations, with some of the high speed lines affected by Friday’s disruption.
Hundreds of thousands are set to make rail journeys to the French capital this weekend.
Engineers have worked overnight to repair cables and signal stations.
SNCF said: “On the Eastern high-speed line, traffic resumed normally this morning at 6.30am while on the North, Brittany and South-West high-speed lines, seven out of 10 trains on average will run with delays of one to two hours.
"At this stage, traffic will remain disrupted on Sunday on the North axis and should improve on the Atlantic axis for weekend returns.”
SNCF reiterated that transport plans for teams competing in the Olympics would be guaranteed.
