LOS ANGELES — One small plane with two men aboard and another plane with a woman aboard collided over the ocean near the Port of Los Angeles, setting off a major search for survivors or bodies, the U.S. Coast Guard said.

The collision occurred about 3:30 p.m. Friday on a sunny day, with no immediate word on what might have caused it.

Men ages 61 and 81 were believed to be aboard one plane. Wreckage and a pilot’s logbook have been found from that plane.

The other plane was flown by a 72-year-old woman. That plane is missing.