The Pentagon is planning to send up a number of planes with high-tech surveillance equipment to help track a sniper in the Washington area who has eluded law enforcement officials for two weeks while killing nine people and injuring two more.

The number of planes, exactly what high-tech capabilities they bring to bear, and when and where they would fly were not being released to withhold such details from the sniper, officials said.

But the planes include the Army's RC-7 Airborne Reconnaissance Low plane and at least one other type of aircraft with surveillance capabilities beyond those of local police forces, defense officials said.

The RC-7 costs $16 million, is 81 feet long, has a wing span of 93 feet and is loaded with state-of-the-art surveillance equipment.

It could provide high-resolution imagery and night vision for such things as tracking the light-colored van that authorities say was seen at one or more of the shooting sites. Infrared sensors that can detect flashes of gunfire on the ground also could be used, officials said.

The plan generally calls for military pilots to fly reconnaissance flights, accompanied by federal agents who would relay any information collected to authorities on the ground, a senior defense official said, speaking on condition of anonymity. A main objective is to improve communications among investigators.