A network-wide system failure at Canadian National has affected rail corridors and forced Toronto-area commuter trains to be halted, Ontario regional transit operator Metrolinx said on Tuesday.

“There is a CN network-wide system failure that is affecting all of our rail corridors. Trains will continue to hold at the nearest stations,” GO Transit parent Metrolinx said in a statement.

GO Transit is the regional public transit service for the Greater Toronto and Hamilton Area. Its trains and buses serve a population of more than seven million people across more than 11,000 square kilometres, according to GO’s website.

Metrolinx said it was working with CN to resolve the issue, and that it was recommending passengers take alternative travel options.

Via Rail said some of its trains entering and departing Toronto’s Union Station will be experiencing delays because of the problems.

“CN is currently experiencing an internet connectivity issue,” the company said in a statement.

There is no indication it is a cybersecurity problem, CN said.

“We are working to get all services up and running safely and efficiently.”