The federal cabinet authorized the RCMP to use counter-terrorism radio jammers to prevent bomb attacks at the international summit in Quebec City last week, government documents show.

The Mounties declined to comment on the measure that Prime Minister Stephen Harper and his cabinet approved less than two weeks before the summit.

But a security expert said there's little doubt interference with cellphones and radio communications at the summit site was a secondary goal of the electronic jamming, the "primary" goal being prevention of electronic detonation of potential explosive devices.

"It's certainly a growing concern at summits, and not only summits," said David Harris, a former chief of strategic planning for the Canadian Security and Intelligence Service. "It's a real pressing issue."

Dignitaries at last weekend's summit included Harper, French President Nicolas Sarkozy, leaders from 52 other member states and governments, as well as observers.

The Harper cabinet passed an order dated Oct. 9 exempting the RCMP from provisions of the Radiocommunication Act that outlaws devices able to interfere with radio and other electronic communications.

"The exemption will apply to the RCMP for the specific dates of Oct. 16 to 19, 2008, and is limited to a narrow geographic area of planned security sites for the Francophonie Summit in Quebec City, Quebec," the order states.

Publication of the cabinet order appears to be a first for the federal cabinet, although Harris was unsure whether that is because it was the first time radio jamming was authorized or whether the government chose to publicize the measure.

"There seems to be an appetite for a bit more openness," said Harris, adding that knowledge of radio jamming in advance might help to prevent terrorist attacks.

He said security officials believe the public is a "generation behind" the reality of the security threat domestically and abroad, and knowledge of some of the new measures being used may make ordinary citizens more aware of the situation.

The Montreal-based RCMP division in charge of the summit would release no details or comment about the jamming system.

"The people here who were responsible for the summit are saying it's a technique, and for that reason we would not be able to comment or give out any information regarding this technique," said Cpl. Elaine Lavergne.