The Predator B drone, the first unmanned aircraft system to patrol the northern U.S. border, left, is followed by a chase plane as it lands at the Grand Forks air force base in December 2008. ((John Stennes/Herald/Associated Press))

The first unmanned surveillance aircraft started patrolling the Manitoba portion of Canada's border with the U.S. after a launch ceremony was held on Monday.

Based at a military facility in Grand Forks, N.D., the $10-million Predator B drone aircraft are equipped with sensors capable of detecting a moving person from 10 kilometres away.

The aircraft is able to fly at an altitude of 6,000 metres and can remain in the air for 18 hours.

The planes will gather information as they fly along the 400-kilometre border and transmit it to operators who will in turn contact border agents. The drones will not carry weapons, such as missiles or laser-guided bombs, and the U.S. will need permission to send them into in Canadian airspace.

Manitoba has 12 official border crossings — only two are open 24 hours a day. Much of the land in between the crossings is either swampland, lakes or farmers' fields.

U.S. authorities are concerned that the border has areas that could potentially be exploited by drug smugglers, migrants and terrorists.

"They will try to find the weakest link, and the weakest link is clearly the long border between the U.S. and Canada," North Dakota Democratic Sen. Byron Dorgan said. "It's very hard to patrol every square mile."

RCMP Staff Sgt. Ron Obodzinski said the surveillance planes will be a big help in the fight against the smuggling of drugs, alcohol and people.

"The program is going to enhance our relationship between our American partners and the Canadian agencies," he said.

U.S. border protection official Michael Kostelnik said that in these "dangerous times," it's more important than ever for both countries to know who and what is crossing the border.

"There are vast parts of the border where, on any given day, we're not sure what's going on, so part of this is to try to deal with the unknown and not be surprised," Kostelnik said.

Similar drones patrol the skies in Iraq and Afghanistan. The aircraft are also used along parts of the U.S.-Mexico border.

Monday's drone launch comes a day before Janet Napolitano, the new secretary of U.S. Homeland Security, is to get a review of the security efforts along the Canadian-American border, and just three days before U.S. President Barack Obama's first visit to Canada.