Nine supporters of the Tamil Tigers rebel group, including four Canadians, are facing charges they conspired to buy surface-to-air missiles from undercover agents in the United States.

The three men visited New York from Canada to purchase weapons -- including Russian missiles, launchers and AK-47s -- which they allegedly planned to send back to rebel forces in Sri Lanka, allege U.S. officials.

Court documents claim the men visited Long Island on Aug. 19 in a bid to obtain $900,000 worth of weapons. The weapons were going to be used to attack fighter jets and ships in Sri Lanka, officials claim.

"The Tamil Tigers are unique in that they are a terrorist group with their own shipping line," the Mackenzie Institute's John Thompson told CTV Newsnet.

"They... never had much of a problem in the past acquiring arms and bringing them in (to Sri Lanka)."

Officials also allege that the men attempted to bribe U.S. officials for classified information while lobbying to get the Tamil Tigers removed from an American list of terrorist organizations.

The charges also accuse the men of conducting fund raising and money laundering using American bank accounts and charitable organizations as a front.

Canada added the Tamil Tigers, which has fought for an independent state in Sri Lanka since 1983 for the 3.2 million ethnic Tamil minority, to its own official list of terrorist organizations in April.

The designations ban the group from raising money, obtaining weapons or lobbying for support.   

Six of the nine men charged appeared at a federal court hearing in Brooklyn and were ordered held without bail. If convicted, they could face up to 15 years in prison.

An FBI affidavit says one of the Canadians, Sathajhan Sarachandran, told the agents he was taking direction from Pottu Amman, the man alleged to have masterminded the 1991 assassination of Rajiv Gandhi, India's former prime minister.

Sahilal Sabaratnam and Thiruthanikan Thanigasalam, both Canadians, were also arrested in the United States.

RCMP officers also raided an undisclosed location in southern Ontario and arrested a fourth Canadian suspect, 26-year-old Suresh Sriskandarajah, Sgt. Michele Paradis told the Toronto Star.

He faces extradition to the United States.

There has been a recent surge in fighting in Sri Lanka since late last year -- four years after the Tamil Tigers and Sri Lankan government reached a ceasefire brokered by Norway.

Foreign Affairs Minister Peter MacKay called last week for an immediate end to hostilities that have killed hundreds of people, mostly civilians, and a return to negotiations.

Most of Canada's Tamil population, fleeing the longstanding civil war, is located in Toronto.

Human Rights Watch says the group has become an important source of income for the Tamil Tigers.

The Canadian Security Intelligence Service said in 2000 that at least eight non-profit groups and five companies were operating in Canada as fronts for the Tamil Tigers.

With files from The Canadian Press