Following State Department accusations that arms shipments are arriving in Nicaragua from Cuba, Defense Minister Humberto Ortega said today that the Cuban ship Aracely had arrived on his country's Caribbean coast bringing "all types of materials."

He told a news conference that U.S.-backed anti-Sandinista guerrillas attacked 30 militia members deployed to guard the route between the port, where the ship arrived, and Managua. Ortega charged that the attack Sunday was directed by the CIA and was designed to cut communications between the port and the capital.

"The mercenary forces of the United States were sent as a consequence of the scandal created . . . over supposed armaments that were supposedly being shipped to Nicaragua in that boat," he said.

"There is no reason for us to give explanations to anybody or ask permission . . . for the things that Cuba and Nicaragua decide to transport in their ships and planes."

Diplomats and military analysts here have said that arms shipments appear to have been arriving in Nicaragua for more than a month but that the content of the shipments is not clear. One foreign military analyst said that SA2 and SA3 antiaircraft missiles may have arrived.

"We haven't physically seen them, we just have some possible, and possibly flaky, sightings," he said. SA2 and SA3 missiles, which Nicaragua has not been known before to have, are surface-to-air missiles capable of knocking down combat aircraft.

Analysts here noted that the weapons are defensive. Such a missile "is not going to reach out and hit Honduras," said the military analyst.