By Laura L. Myers

SEATTLE (Reuters) - A plan by Seattle police to send aloft miniature robot drones equipped with stealth spy cameras has been grounded, following heated criticism of the project by residents concerned about privacy rights, the mayor said on Thursday.

Seattle Mayor Mike McGinn said he and Police Chief John Diaz decided to cancel the use of two unmanned helicopters to better focus on maintaining the public's trust.

The miniature helicopters, known as Draganflyer X6 drones, weigh 3.5 lbs (1.6 kg) and are equipped to carry video, still and night-vision cameras. In Seattle, they would have been used to search for missing persons and in certain criminal investigations, police said.

The aircraft would not carry weapons but the use of drones for even mundane tasks raises ire among some because of the association of pilotless crafts with covert U.S. missile strikes in places such as Pakistan and Yemen.

Plans by a number of U.S. law enforcement agencies to use drones represent a new and controversial frontier for the technology.

A recent push for unmanned police aircraft was driven by U.S. Department of Homeland Security grants, including $80,000 used by Seattle to buy the eye-in-the-sky choppers in 2010.

"We agreed that it was time to end the unmanned aerial vehicle program, so that SPD can focus its resources on public safety and the community building work that is the department's priority," McGinn said in a statement.

The drones, which could only remain aloft for 15 minutes before their batteries ran out, will be returned to the vendor, McGinn said. Continued...