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.

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

'This is a massive attack on a large scale to paralyse the TGV network,' SNCF told AFP, adding that many routes will have to be cancelled.

'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' and the situation would last through the weekend as repairs are conducted.

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'.

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