TOKYO, June 23 (IslamOnline.net & News Agencies) - North Korea warned Monday, June 23, of "merciless strikes" against U.S.-led moves to clamp down on its alleged illicit activities after ditching its only regular ferry run to Japan for the second time in two weeks.

Man Gyong Bong-92, the ship at the center of spying and smuggling allegations, would not arrive as scheduled in Niigata on Monday from the North Korean port of Wonsan, Agence France-Presse (AFP) quoted a group of pro-Pyongyang ethnic Koreans as saying.

Pyongyang's official Korean Central News Agency (KCNA) said the cargo-passenger ship had been barred as part of the measures which Japan and the United States recently discussed in seeking to intercept North Korean ships that allegedly smuggle drugs, weapons and counterfeit money.

Japan was acting as a "shock brigade" in implementing a U.S. plan to forge an allied front in its "psychological warfare and blockade operation" against North Korea, KCNA said.

North Korea "is neither a rogue state (a groundless label attached by the U.S. to it) nor a country that would yield to the U.S. pressure," the KCNA said.

North Korea further warned the U.S. and "its followers of infringing upon the sovereignty of the DPRK (North Korea) even a bit," threatening that "it will retaliate against them with merciless strikes."

The pro-Pyongyang group, the General Association of Korean Residents in Japan (Chongryon), said the ship could not enter Niigata "as the situation has not improved."

North Korean authorities "point to the discriminatory behavior on Japan's part," said So Chung-On, a senior international bureau official at Chongryon, which represents North Korean interests in Tokyo in the absence of diplomatic ties with Japan.

At a U.S. Congressional hearing last month, a man claiming to be a former North Korean engineer testified that the Man Gyong Bong-92 had been used by Chongryon regularly to smuggle missile parts to North Korea.

Japan's intelligence agency said earlier a senior North Korean agent had come to Niigata aboard the ship to convey instructions to operatives in Japan.

The allegations have been flatly denied by Chongryon.

The ship cancelled at the last minute its scheduled round-trip on June 9, following Tokyo's vow to beef up security, customs and technical checks on ships from the Communist state entering Japan.

The Chongryon spokesman said it was still unclear whether it would make its next port call scheduled for July 3.

In past weeks, several North Korean ships have been stopped from leaving port for forced repairs on their technical defects.