Zakaria Amara studied how to make fertiliser bombs on the internet
One of the key figures in a conspiracy to set off three truck bombs in Canada has been sentenced to life imprisonment.
Zakaria Amara, 24, pleaded guilty in October to co-leading the Islamist militant group dubbed the Toronto 18.
The group's targets included the city's stock exchange and a military base.
Sentencing Amara, who was arrested in 2006, Ontario judge Bruce Durno said that he had planned the most horrific crime in Canadian history.
The trial had heard how Amara learnt how to make a fertiliser bomb on the internet.
Shortly after his arrest, Canadian police detonated an imitation one-tonne bomb in a controlled explosion to see what effect it would have.
They determined that many hundreds of people could have been killed had a similar device gone off outside Toronto's stock exchange.
Last week, at his sentencing hearing, Amara read out an open letter to Canadians, saying that he had completely renounced his extremist ideology and apologising for the harm he had caused.
The planned truck bombings were part of a wider plot by the terror cell to carry out a series of attacks in Ontario province, the BBC's Lee Carter reports from Toronto.
They included storming the parliament buildings in the capital, Ottawa, and beheading the prime minister.
There is conflicting evidence about how far these plans actually advanced.
Hours earlier, Saad Gaya, another member of the group, was sentenced to 12 years in prison.
Of the 18 people arrested in 2006, seven have had their charges dropped.
Five are still awaiting the start of their trials.