Paris, France - France's high-speed rail network was hit by "malicious acts" including arson attacks that have disrupted the transport system, train operator SNCF said Friday, hours before the opening ceremony of the Paris Olympics.

"This is a massive attack on a large scale to paralyze the TGV network," SNCF told AFP, adding that many routes will have to be cancelled and the situation would last "at least all weekend while repairs are conducted."

"SNCF was the victim of several simultaneous malicious acts overnight," the national train operator said, adding that the attacks affected its Atlantic, northern, and eastern lines.

"Arson attacks were started to damage our facilities," it said, adding that traffic on the affected lines was "heavily disrupted."

Trains were being diverted to different tracks "but we will have to cancel a large number of them," the statement said.

The southeastern line was not affected as "a malicious act was foiled."

A source close to the investigation told AFP the attacks were coordinated acts of "sabotage."

SNCF urged passengers to postpone their trips and stay away from train stations.

The attacks were launched as Paris prepares for the Olympics opening ceremony, with 7,500 athletes, 300,000 spectators, and an audience of VIPs.