Updated

Canadian authorities decided to move quickly against a suspected homegrown terror ring and head off any attack on Ontario targets after undercover Mounties delivered bomb-making materials in a sting operation, according to a news report Sunday.

The Toronto Star said the Royal Canadian Mounted Police itself delivered the three tons of ammonium nitrate that authorities reported Saturday had been acquired by a group of Muslims apparently inspired by Al Qaeda.

Once the deal was done, police moved in for the arrests, the Star said. It added that investigators had learned of the group's alleged plan to build a bomb and then controlled the sale and transport of the fertilizer.

CountryWatch: Canada

It was not clear how the sting sale developed, and there was no indication of whether police might have altered the fertilizer to make it unusable in a bomb.

Authorities refused to discuss the Star's story. They have revealed few details of the purported plot, news of which was followed by vandalism against at least one mosque and e-mailed threats to Muslim leaders.

Police officers are saying privately that Web surfing and e-mail among the suspects initially led to the investigation beginning in 2004, something that Canada's ambassador in Washington, Michael Wilson, alluded to in an interview with CNN's "Late Edition."

"My understanding of it is that the Internet played a very important part of it. Whether there was a direct inspiration or an indirect inspiration, the Internet was, according to the police, a very important part of their activities," Wilson said.

U.S. Secretary of State Condoleezza Rice said the Canadian operation was "obviously a great success for the Canadians. They're to be congratulated for it."

Police arrested 12 adults, ages 19 to 43, and five suspects younger than 18 Friday and Saturday on terrorism charges, including plotting attacks with explosives on Canadian targets. The suspects were citizens or residents of Canada, and police said they had trained together.

Cpl. Michele Paradis, a spokeswoman for the Mounties, disagreed with a government official who said privately that more arrests might be made this week.

"Not right now," she said. "Once we analyze and sort through everything that was seized as a result there may be. At this point we are confident that we have the majority of people."

The 17 suspects represent a broad spectrum of Canadian society, from the unemployed to the college educated. The 12 adults live in Toronto, Mississauga and Kingston, Ontario. The five youths cannot be identified under Canadian law.

Rocco Galati, a lawyer, said he represented two of the men from Mississauga, an immigrant-rich town just east of Toronto.

He described Ahmad Ghany, 21, as a health sciences graduate of McMaster University who was born in Canada. Ghany's father is a physician who emigrated from Trinidad and Tobago in 1955, Galati said.

His other client, Shareef Abdelhaleen, 30, is an unmarried computer programmer of Egyptian descent, Galati said. He emigrated from Egypt at age 10 with his father, who is an engineer on contract with Atomic Energy of Canada Ltd., a private firm that provides services to nuclear utilities in Canada and other countries.

"Both of their families are very well-established professionals, well-established families, no criminal pasts whatsoever," Galati said. "That's why we're anxious to see the particulars of the allegations against them."

Two suspects, Mohammed Dirie, 22, and Yasim Abdi Mohamed, 24, already are in an Ontario prison serving two-year terms for possession of illegal weapons. Dirie's family moved to Canada from Somalia when he was 7 years old, said Omar Jamal, executive director of the Somali Justice Advisory Center in Minnesota, who was contacted by Dirie's mother about legal representation.

"What we're concerned about is the basic erosion of civil rights," said Jamal. "Governments use information that is secret because of security issues, they claim. So we hope that the Canadian government and the police will respect the basic rights of these individuals."

Officials said the 17 arrests came after a lengthy operation involving some 400 intelligence and law-enforcement officers and was the largest counterterrorism operation in Canada since the adoption of Canada's Anti-Terrorism Act following the Sept. 11 attacks on the United States.

Toronto Mayor David Miller said he was told by the city's police chief several months ago that a suspected terrorist cell was being investigated in the Toronto area.

"I was relieved that police had discovered the activities at a very early stage," Miller said. "I was relieved on behalf of Torontonians because I knew because of the police activities that if there was an actual threat, they would be able to stop it before anything serious happened."

Mike McDonnell, an assistant commissioner with the Mounties, said Saturday that the amount of ammonium nitrate acquired by the alleged terror cell was three times that used by American anti-government extremists to blow up the Alfred P. Murrah Federal Building in Oklahoma City in 1995, killing 168 people and injuring more than 800.

The fertilizer is safe by itself, but when mixed with fuel oil or other ingredients, it makes a powerful explosive.

The FBI said the Canadian suspects might have had "limited contact" with two men recently arrested on terrorism charges in the U.S. state of Georgia. There was no indication Sunday, however, that the 17 detainees were trying to plan an attack in the United States.

"We certainly don't believe that there's any link to the United States, but obviously we will follow up," Rice said on CBS's "Face the Nation," noting the investigation was continuing.

Aly Hindy, an imam of Scarborough's Salaheddin Islamic Center, said he knew nine of the suspects and complained that Canada's spy agency, CSIS, has unfairly targeted his mosque and congregants for years.

"They have been harassed by CSIS agents and this is what they come up with?" Hindy said. "I'm almost sure that most of these people will be freed."

Hindy predicted the case would end up like a 2003 high-profile security investigation that ended up embarrassing authorities.

That case, a joint immigration and Mountie investigation, was touted as the dismantling of an al-Qaida cell. Twenty-two Pakistani students and an Indian national were arrested, but it ended up being just an immigration case that sent the students home branded as terrorists.

Mohammed Abdelhaleen, the father of one of the those arrested over the weekend, was alarmed by the huge police presence at Saturday's court hearing, where snipers perched on nearby rooftops and dozens of officers armed with M-16 assault rifles guarded the entrance.

Abdelhaleen said he feared his son had already been convicted in the court of public opinion. "The damage has already been done," the father said. "He just goes and prays in a mosque. That's all he does."

Muslim leaders voiced worries that the highly publicized arrests would cause a backlash against their community of 750,000 people.

A mosque in northwest Toronto was vandalized overnight, with 25 windows and three doors smashed, police said. Enuof Baksh, the building's caretaker, said people were distraught when they saw the broken glass Sunday morning.

Mohamed Elmasry, president of the Canadian Islamic Congress, told AP that he and other Muslim leaders were getting threatening e-mails.

He said Muslims would now have to deal with hate crimes, as they did after the Sept. 11 attacks and deadly bombings in London and Madrid, Spain.

"It's already happening. A mosque was vandalized. We hope Canadians will be more rationale and consider the facts," Elmasry said.