OTTAWA — Police in Ottawa have arrested two men in connection with an alleged al-Qaida-related terrorism plot after searching two residences on the city's west side.

The RCMP said in a news release that they were executing a number of search warrants and additional arrests were expected, including across the Ottawa River in Gatineau, Que.

Police have been investigating the alleged plot for two years. It has apparently been dubbed Operation Samosa.

"These guys were doing more than just talking about terrorism. They were planning it," said a police source.

The National Post reported the investigation involves an alleged al-Qaida plot and that the ringleader is believed to have trained in Pakistan and Afghanistan. The Post said the investigation involved a bomb plot, though it was not well-defined and the arrests were made because one of the suspects was preparing to travel abroad.

Ottawa defence lawyer Samir Adam met for more than half an hour with one of the accused at Ottawa police headquarters early Wednesday but had not been officially retained as counsel as of late Wednesday afternoon.

Adam would not disclose what the two discussed but said he expects the accused to appear in court on Thursday.

Police said they will release additional details about the investigation at a news conference on Thursday at 1 p.m.

Neighbours say they saw police arrive at the first house before 7 a.m. Wednesday. At least five Ottawa police cars and one RCMP cruiser were parked on the street. Neighbours say they also saw several unmarked police cars in the area. They described the residents of the house as devout Muslims.

A vehicle was removed during the search of the first residence. Police also hauled several computer hard drives out of the home. Another officer brought out what appeared to be a scanner.

Louise, who lives next door to the home and would not give her last name, said the woman who lived there wore a burqa. She often heard the couple chanting some kind of prayer in the morning.

"It's quite scary, actually," Louise said. "We are trying to process all of that. It's quite the surprise."

At the second residence searched, RCMP and Ottawa police officers stood watch Wednesday afternoon. Most were stationed on the seventh floor of the building where a specific unit was being closely guarded.

In the early afternoon, investigators could be seen bringing empty cardboard boxes inside the building.

Anthony Seaboyer, head of the proliferation security research group at Queen's University's Centre for International Relations, called the arrests "a great success" for Canadian anti-terrorism forces.

"It shows that the RCMP, Ottawa police and CSIS can actually co-operate effectively," Seaboyer said.

Given the scathing criticism of how security authorities handled the Air India bombing, "this is a good sign," he said.

"Canada is moving more and more away from being a safe haven for terrorist organizations."

On the other hand, Seaboyer said, "it shows what's now going on out there. We have now found one group, but what else is out there?"

It's impossible to know how many terrorism cells are active in Canada, Seaboyer said, but those arrested Wednesday are "definitely not the only group out there, that's for sure."

He said Canada is becoming more of a target for terrorists who want to use attacks on Canadian facilities, such as Quebec's hydro-electric plants and transmission lines, to harm the United States.

"There are ways of attacking the U.S. through Canada. The whole energy for New York comes from Quebec, for example."

With files from Kristy Nease, Meghan Hurley, Don Butler, Chris Cobb and Gary Dimmock, Ottawa Citizen