Police found about 400 marijuana plants in Wednesday's operation. They were brought to Charlottetown and burned. ((CBC))

A low-flying police helicopter is patrolling the skies over Prince Edward Island this week on a seek-and-destroy mission to find drugs.

The primary target is marijuana, and on Wednesday, the first day of the aerial search, police discovered about 400 mature marijuana plants in fields and wooded areas in eastern P.E.I.

Sgt. Denis Morin of the RCMP said the plants were taken to a waste facility in Charlottetown and burned.

He said police do not have special equipment for finding the drugs but rely on sharp eyes and good information about where the plants are likely to be growing.

"Mostly in isolated areas, areas where we would have trouble accessing, so we use this as a tool to fly over and see exactly the area and then eradicate the plants that we find," he said.

"They know what to look for; they can recognize those plants very quickly. The way they're harvested and planted, that's what they go on."

The operation is part of a national program to eradicate marijuana plants. It does not focus on identifying the growers and charging them, but that does happen when they find large operations.

RCMP said they carry out aerial searches about once a year, just before the plants are set to be harvested.

"It's still going to be going on for the next few weeks and months," Morin said. "We know we still have a few good months of harvest ahead of us, so it's an ongoing program. There is going to be more effort and follow up to what we've found."

The aircraft targeted western P.E.I. Thursday.