A series of fires has hit French high-speed rail lines, hours before the Paris Olympics opening ceremony
Rail company SNCF says it's a "massive attack aimed at paralysing the network"; France's transport minister condemns the "co-ordinated malicious acts"
Some 800,000 customers will be affected with disruption expected all weekend, the rail firm says
One in four Eurostar services will be cancelled until Monday
Authorities have moved quickly to bring in an expert to understand how a country's rail network can be crippled so quickly