A vital oil terminal here was functioning normally this afternoon two days after U.S.-sponsored guerrillas claimed to have sabotaged it with explosives.

A half-hour tour of the facility by two U.S. reporters showed no sign of damage. Warm liquid appeared to be flowing within the pipeline leading out of the terminal and an electrical turbine nearby hummed peacefully.

"All of these rumors spread by the contras (counter-revolutionaries) are part of psychological warfare," said Osberto Camacho, the military officer in charge of operations at this Pacific port of 7,000 persons. He hesitated when the reporters showed up unannounced and asked to visit the oil terminal, but said that he would permit the tour "to show that nothing happened."

The Honduras-based Nicaraguan Democratic Force announced the alleged attack on Thursday, saying that it had been carried out by an officer in the Sandinista Army, who was secretly working for the rebel guerrillas, and by an "adviser." The Nicaraguan government yesterday denied that any attack had taken place.

The terminal receives oil from tankers that dock at buoys in a bay and then pumps the petroleum to a refinery. About two dozen soldiers with rifles and machine guns could be seen guarding the terminal, which was surrounded by two high metal fences topped by barbed wire.