America Could Face Home-Grown Threat

The 17 arrested in Canada allegedly have ties to two men from Georgia who were arrested earlier this spring. After the arrests, the FBI accused the Georgia suspects of gathering information about Washington D.C., oil refineries and military installations.

Tonight, police in the United States are looking for any other connections to the Toronto cell.

The Canadian public safety minister said he's been in touch with U.S. officials to assure them that the 17 men under arrest had no plans to attack any targets in the United States.

Alleged Actions and Ideology, Not Religion

In Toronto today, police officials assured the Islamic community that the 17 people under arrest were targeted because of their alleged actions, not their religion.

"There is no accusation against the Muslim community by law enforcement," Toronto Police Chief Bill Blair said. "Our accusations pertain only to the actions of 17 young men."

Those young men, mostly Muslims of South Asian descent, have been charged with plotting attacks on Canadian targets. Police said they had three tons of fertilizer -- the same material that fueled the 1995 Oklahoma City bombing.

"These are people diverse backgrounds, a variety of backgrounds and ages, certainly inspired by terrorist ideology but operating within their own network," said Stockwell Day, Canada's minister of public safety.

It's a big concern for officials in the United States, where Islam is the fastest growing religion. There are seven million Muslims in America, 2.3 percent of the population. Most of them have no terrorist intentions -- which is also true for millions of Muslims in Canada.

"But those 17 people, using dual-use material available at hardware stores and at farm stores, could have done enormous damage," Clarke said.

ABC News' John Yang and Pierre Thomas reported this story for "World News Tonight."