Maritime Self-Defense Force destroyers early Wednesday gave up chasing two mystery trawlerlike vessels that had intruded into the nation's territorial waters in the Sea of Japan before fleeing toward North Korea, Defense Agency officials said.

The officials also said Air Self-Defense Force E-2C early-warning aircraft confirmed by radar that more than two North Korean MiG-21 jets were flying toward the fleeing boats at 7:55 a.m. Wednesday. They would not state the number of E-2Cs dispatched.

The sea chase was terminated when the intruding ships, bearing the names of Japanese fishing boats, left Japan's Air Defense Identification Zone, Defense Agency chief Hosei Norota said.