OTTAWA — The Canadian Navy and Coast Guard intercepted a ship off the coast of British Columbia Thursday afternoon that was thought to be carrying hundreds of Tamil migrants from Sri Lanka.

The Canadian authorities had been tracking the ship since it set sail from Sri Lanka many weeks ago. Vic Toews, the public safety minister, told reporters on Thursday that some of the ship’s 490 passengers were “suspected human smugglers and terrorists.”

Many members of the Tamil community in Canada, however, rejected assertions that the passengers were linked to the Liberation Tigers of Tamil Eelam, known as the Tamil Tigers, a militant group that had been fighting for a Tamil homeland in Sri Lanka until it was defeated by the military in May 2009.

While Mr. Toews initially indicated that the Royal Canadian Mounted Police had boarded the ship, the prime minister’s office said later that the vessel was being escorted to a naval base near Victoria, British Columbia.

Tents were erected at the base over the past few days and a large force of police officers and immigration officials gathered. In addition, jails in British Columbia were readied.

It was anticipated that the passengers on the ship would argue that they were fleeing persecution in Sri Lanka and that they would request permission to remain in Canada as political refugees, as did 76 Tamil migrants who were on a ship that approached Canada in October.

While he provided no details, Mr. Toews said that the government intended to demonstrate with this case that it would not tolerate human smuggling.

“Human smugglers and human traffickers are now watching Canada’s response to judge whether or not they can continue to take advantage of us,” he said at a news conference.

Mr. Toews said Canada would send a message to human smugglers: “If you do this, you will be prosecuted to the fullest extent of the law.”

Hospitals in the Victoria area were told to be ready for people who might be ill.