U.S. Abassador to El Salvador Robert White said today that he had received information indicating that the Salvadoran National Guard and local political officials may have been aware of the whereabouts of the bodies of four American women slain here for at least a day before church officials finally found them as a result of independent information.

The four women -- three nuns and a social worker -- disappeared Tuesday and their bodies were exhumed yesterday from a common grave alongside a country road.

A representative of the San Salvador Roman Catholic Archdiocese said church investigators believed that National Guard troops may have been involved in the killings.

Ambassador White's comments came at a funeral mass for the four women following an announcement in Washington that the United States had suspended all economic and military assistance to the government pending an investigation of alleged involvement of government forces in the women's deaths.

Until now, the U.S. government has steadfastly defended the country's civilian-military junta from charges by human rights organizations and church officials and backed the junta's contention that terrorist killings have been the work of leftist guerrillas and extreme rightists unconnected with the government.

The dead women were identified as Ita Ford, 40, and Maura Clarke, 46, of the Maryknoll order, Dorothy Kazel, 40, of the Ursuline order, and lay worker Jean Donovan, 27. d

White said he had received "information about the times certain things occurred that are really very important" from a local justice of the peace who supervised the burial of the four women near a remote road south of the capital. He said the official allowed him to reconstruct a chronology of the killings.

The women were killed about midnight Tuesday, he said, and their bodies were discovered alongside the road in the very early morning by peasants. The justice of the peace was summoned to the scene, and when he arrived there was already a six-foot-deep trench.

The justice of the peace allowed the bodies to be buried without indentification, and a diplomatic source said yesterday that the National Guard contingent was present at the burial site and forced the justice of the peace to accept a fait accompli that he could not reject or change.

"I as a former ditchdigger can tell you it takes a long time to dig a trench that large," White said today. He said that at a maximum, only five or six hours elapsed between the deaths and the presence of the National Guard soldiers on the scene.

White said the embassy was first notified about the bodies in the middle of the afternoon Wednesday and called Col. Jose Gullermo Garcia, the minister of defense, and other Salvadoran government officials.

"They told us they were unaware" of any bodies being found, White said. That means, he explained, that several government officials at least at lower levels must have been aware that the bodies of four women who looked like Americans had been found several hours before the embassy even inquired about them.

But he said the government's knowledge of the whereabouts of the bodies was not revealed until after Catholic Church sources had discovered the bodies independently.

White also said that yesterday morning -- some 24 hours after the justice of the peace presided over the burial -- government officials were still saying that they knew nothing about any bodies. White called that "bizarre."

White met with the junta and the military commanders to express the "shock and outrage" of the United States, he said. The Salvadoran officials expressed "profound regret for what happened and promised a thorough and profound, far-reaching investigation."