A light plane carrying President Ferdinand Marcos on an election campaign swing in the central Philippines narrowly missed colliding with another aircraft today when security men ran onto a runway to prevent the two planes from landing at the same time.

The incident at Calapan on the island of Mindoro Oriental came amid denials by the government that Marcos' health is deteriorating. The president appeared at Calapan with a bandage around his left hand and wrist and bandages on his left forearm and right hand for what he said were "scratches" when a woman tried to grasp his hands during an earlier campaign stop.

The official Philippine News Agency said Marcos was unaware of the near collision on Calapan's grass airstrip. But reporters at the scene said he appeared pale and shaken afterward and dropped his glasses before getting into a car.

Marcos' six-seat, twin-engine Beechcraft had just touched down when a single-engine Philippine Air Force Cessna made a landing approach from the opposite end of the airstrip on what the official news agency said was a "collision course."

Security men awaiting the president frantically ran onto the airstrip and waved their arms to alert the planes, western news agencies reported. The Cessna then aborted its landing, soaring up and banking to the right about 500 feet ahead of the president's plane.