Two accused terrorists planning the first al-Qaeda attack on Canadian soil received help from within the United States, authorities say.
Chiheb Esseghaier, 30, a Tunisian-born doctoral student, faces charges including conspiracy to murder and working with a terrorist group.
He and co-defendant, Raed Jaser, 35, are accused of plotting to bomb a train between New York and Montreal.
The Royal Canadian Mounted Police, who carried out the arrests on Monday on behalf of the country's Security and Intelligence Service, say at least two American citizens from New York City were also involved in the plot and were under FBI surveillance.
Officials say the plot was supported by al-Qaeda elements in Iran.
During a brief hearing at a court in Toronto on Wednesday, Mr Esseghaier said the allegations against him are based on laws that are unreliable because they are not the work of God. He was ordered back into custody.
Mr Esseghaier and Mr Jaser have said they will challenge the case against them. They are due to return to court on 23 May.