By BOB WILCOX

An explosion - apparently a bomb - severely damaged an engine of a converted B25 bomber loaded with CARE packages for Cuba today while the aircraft was parked at Miami airport.

The blast at 3 a.m. did not injure anyone. The twin-engine plane was in a parking area to the NW corner of the airport.

R. Napokx, a customs agent, said the place was fully loaded with medicine, food and clothing that was to have been flown to Merida, Mexico, and then on to Cuba.

The loading was completed late yesterday afternoon and the craft was to have taken off today.

Napoles said the blast looked like a bomb job to him.

The FBI took over the investigation and would not make a statement. Other officers, however, speculated that the bombing may have been connected with one of Miami's many anti-Castro Cuban groups.

John Puccerella, ramp supervisor, said he understood the explosion was at 3 a.m. but the damaged plane was not discovered until about 8 a.m.

Whatever caused the explosion, it blew out the rear end of the engine mounted in the left wing of the plane. Pieces of twisted metal were scattered nearby.

The plane is registered to Ramon Masse of Merida. Jorge Erales was listed as the pilot and Pastor Coello as copilot. Both are from Merida.

The aircraft arrived here yesterday from Mexico.

B25s were first produced in World War II as medium bombers but soon were dropped to light bombers when the heavier planes rolled off the assembly lines.

Gen. James H. Doolittle, then a lieutenant colonel, led a flight of 16 B25s in a raid on Tokyo, Nagoya and Kobe.

The planes took of from the deck of the aircraft Carrier Hornet on April 18, 1942, when the ship was 688 miles from Tokyo