The State Department warned American citizens yesterday to avoid travel to the Sudanese capital of Khartoum and withdrew some embassy personnel there because of the presence of "known terrorists" and "possible threats to U.S. interests."

State Department spokesman Charles Redman said the United States is recalling about 10 percent of U.S. employes and their dependents stationed in Khartoum because of the threat.

About 600 U.S. diplomats and private Americans are in Khartoum, a U.S. official said. About 1,000 other Americans are living and working outside the capital.

Redman said that most of the known terrorists are Libyan but that some were from other countries and organizations.

A U.S. official said some of the Libyans known by American authorities to be present in Khartoum have been involved in terrorist incidents. "These are known Libyan terrorists on the streets of Khartoum," he said.

Redman said the Sudanese government has been "very cooperative" in providing security forces to guard the U.S. Embassy and other U.S. government buildings but added, "It has not responded to our concern about the presence of terrorists."

"We've not had a satisfactory response," he said.

One cause of concern to U.S. officials is the presence of the Libyan national airline office in the same building as and just below the offices of the U.S. Agency for International Development.

Redman was also critical of the trials under way in Khartoum of former vice president Omar Tayeb and others held responsible by the military group that overthrew President Jaafar Nimeri last April for allowing Ethiopian Jews to leave the Sudan on U.S.-provided planes for Israel.

"We feel that the trials have distorted America's humanitarian motive in the airlift," he said, adding that the United States is also concerned that they would provoke "anti-American feeling in Khartoum."