IT WAS authoritatively reported this evening that the aircraft carrier Enterprise and other United States naval units had been ordered to move into the Sea of Japan in the direction of the North Korean port of Wonsan.

Reports that North Koreans had seized the United States Navy intelligence ship Pueblo and forced it to enter Wonsan had earlier aroused angry reaction in Washington. A White House spokesman said it created “a very serious situation”.

The nuclear-powered Enterprise, the most powerful ship of the Seventh Fleet, which had been visiting the Japanese port of Sasebo, was said to have sailed south when it left there yesterday. But then it received orders to turn north and join other units headed into the Wonsan area.

The Pentagon said that four crew of the Pueblo had been wounded, one critically. But it declined to say how the wounding had occurred.

A broadcast from North Korea confirmed the seizure of the Pueblo, saying it took place in North Korean territorial waters. It said “United States imperialists” had sent the Pueblo “to intrude into the waters off Wonsan and perpetrate serious provocations”.

Mr Robert McCloskey, the State Department spokesman, when asked to comment on the North Korean charges that the Pueblo had been engaged in “serious provocations” replied “There is nothing provocative about a vessel in international waters”. He had no reason to believe the Pueblo might have been in North Korean waters and then moved out to the high seas before being captured.

State Department sources indicated that the Pueblo, described as a naval intelligence collection auxiliary ship, had been stationed off the North Korean coast for the past two weeks. The United States has two avenues of appeal, they said. One is through Moscow, and it is understood that the Soviet Union has already been asked to use its good offices in the incident. The other is through the Korean Armistice Commission.

The Defence Department said that the final message from the Pueblo after she had been surrounded by four North Korean patrol boats, boarded and ordered to put into Wonsan was received at 12.30am. Eastern Standard Time. This reported that the ship had come to “all stop” and that it was “going off the air”. Her crew consisted of six officers, 75 enlisted men and two civilians.

First reactions on Capitol Hill to the seizure of the Pueblo were angry.

Senator Richard Russell of Georgia, chairman of the armed services committee, said that the North Korean action was “a serious breach of international law, amounting to an act of war”.

Senator Mansfield, the Senate Democratic leader, agreed that the incident was“a clear violation of international law”.

Senator William Fulbright chairman of the foreign relations committee commented that “the fact we are deeply committed in Vietnam undoubtedly contributes feeling more free than normal from serious retaliations”.

The Navy said the Pueblo’s only armament was two 50- calibre machine guns. She was equipped with a variety of oceanographic equipment, including depth sounding and underwater topographical devices, as well as electronics and communication gear.

The Defence Department refused to say what the Pueblo was doing off the Korean coast. Officials said only that the ship was engaged in “collecting intelligence” and that in her operation in international waters she was using “electronic means” for this purpose.

The State Department said the subject of the seizure would be raised directly with the North Koreans at an Armistice Commission meeting at Panmunjom tomorrow.