PARIS (AP) — French railway company SNCF said Saturday it has made progress in partially restoring high-speed train services after acts of sabotage disrupted three major lines ahead of Friday night's Olympic Games opening ceremony on the Seine River.

SNCF said its agents worked through the night in adverse weather conditions to improve the TGV 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 South-West high-speed lines, seven out of 10 trains on average will run with delays of one to two hours,” SNCF said.

The company added that traffic will continue to be disrupted on the North axis on Sunday, but conditions are expected to improve on the Atlantic axis for weekend returns. Customers are being contacted via text message and email to confirm the running of their trains.

Despite the disruptions, SNCF said all transportation for Olympic teams and accredited personnel will be maintained as planned.

The sabotage incidents have raised concerns about security as Paris hosts the Olympics. French authorities are actively investigating but say that no suspects have been identified or apprehended so far.