Los Angeles, Feb 7 (IANS) Three people were killed when two small planes collided in the sky over Colorado, authorities said.

The victims were from both of the planes that crashed, Boulder County sheriff's office spokesman Rick Brough said.

One of the aircraft clipped the towline of the other plane that was pulling a glider, the Federal Aviation Administration (FAA) spokeswoman Laura Brown said.

The glider or sailplane apparently disconnected after the collision and landed safely a short time later, Xinhua reported.