OTTAWA - Police have charged three men in what they say was a terror plot that reached from suburban Ottawa to Afghanistan, Iran, Dubai and Pakistan.

Officials said the arrests and seizures — including more than 50 circuit boards designed to remotely detonate bombs — came after a year-long investigation and "extensive surveillance" by police and security forces.

An actual attack was likely still months away, but the police said they moved because they feared the plotters were about to start sending money to other terrorists in Afghanistan to buy weapons to be used against coalition and Canadian troops.

Police described the three as members of a domestic terrorist group.

"The threat of terrorism is very real and Canada is certainly not immune to potential attacks," Raymond Boisvert, assistant director of the Canadian Security Intelligence Service, told a news conference.

"This country has been identified on several occasions as a legitimate target by various individuals who espouse an Islamist ideology."

Hiva Mohammad Alizadeh, 30, of Ottawa faces charges of conspiracy, committing an act for terrorism purposes and providing or making available property for terrorism purposes.

Alizadeh is also charged with making or having "an explosive substance" with the intent to endanger life or cause serious damage to property. Police said the circuit boards are considered an explosive substance under the Criminal Code.

Police said he is also a member of another terror group linked to the Afghan conflict.

Misbahuddin Ahmed, 26, of Ottawa is charged with conspiracy to commit a terrorist offence.

And Khurram Syed Sher, 28, of London, Ont., a medical graduate from McGill University in Montreal, is also charged.

Documents filed in provincial court in Ottawa say the men conspired with three others to "knowingly facilitate terrorist activities" in Canada and abroad.

The additional alleged conspirators named in the court documents are James Lara, Rizgar Alizadeh and Zakaria Mamosta. It is not clear if these men are in Canada. The charges say the conspiracy was carried out in Ottawa, Iran, Afghanistan, Dubai and Pakistan.

The investigation, known as Project Samossa, continues.

The probe brought together the RCMP, Ottawa police, the Canadian Border Services Agency, the Canadian Security Intelligence Service, the Surete du Quebec and the London, Ont., police.

Although the RCMP and CSIS have been faulted for rivalries in the past, they both stressed that this investigation involved the closest co-operation.

Besides the electronic circuit boards, officers seized "a vast quantity of terrorist literature and instructional material ... showing that the suspects had the intent to construct an explosive device for terrorist purposes," the police said.

At least one of the suspects was trained overseas to make explosive booby traps, they said.

"This group posed a real and serious threat to the citizens of the National Capital Region and Canada's national security," said RCMP Chief Supt. Serge Therriault.

Police refused to specify the targets, saying those would eventually be revealed in court.

Therriault said the threat level waxed and waned during the long investigation, as police watched the trio and gathered evidence.

He said a terror attack was still ''months away'' when the arrests were made.

He said investigators seized ''schematics, videos, drawings, instructions, books and electrical components designed specifically for the construction of improvised explosive devices or IEDs.''

Touring the Arctic, Prime Minister Stephen Harper said the arrests should remind Canadians that they face real threats.

"The networks that threaten us are worldwide, they exist not only in remote countries but they have — through globalization and through the Internet — they have links through our country and all through the world," Harper said.

"These things will continue to be challenges but we will continue to work with our police and security agencies to ensure they have the resources to track these threats and respond appropriately and hopefully in all cases before any serious damage is done."

Ahmed's lawyer, Ian Carter, said the charges are serious and his client, a husband and father, could be put away "for a long time."

"He is in shock. That's all I can say," said Carter.

Sean May, Alizadeh's lawyer, said his client "seems to be taking the matter seriously and obviously very concerned about it."

"They are very serious charges, no question about that. They are the most serious charges you can face except for a murder charge."

Ahmed and Alizadeh were brought into court via police van, hiding their faces from cameras.

Tall and slender with square glasses, the bearded Alizadeh wore a checked dress shirt, dark pants and a brown cap. Ahmed, also bearded, wore a white shirt with brown swirl graphic by his right hip.

A judge remanded them in custody until they appear again, by video, next Wednesday.