SANTIAGO (AFP) - All four people aboard a small airplane were killed when it plunged to the ground at an airport north-west of the Chilean capital, police said on Sunday.

The plane crashed at the Chacabuco airport, some 50km from Santiago. General Richardo Soler, head of the regional police, told the daily La Tercera said that officials will probe the cause of the crash.

The victims were two adult men, including the pilot; a younger man and a youth. All died instantly, Gen Solar said.

The airplane, belonging to the Universitario aviation club, left the airport late on Saturday, but began to smoke soon after and slammed into the ground and burst into flames, witnesses said.