The U.S. government may warn U.S. citizens not to travel along certain roads in Mexico because of what it described as a recent rash of violent assaults on visitors to this country, the U.S. Embassy said today.

A Mexican tourism official, while declining to comment formally, suggested that the United States was trying to frighten its citizens away from Mexico as a means of keeping them and their dollars at home.

The official added that about 1.75 million tourists were expected to this year by car, virtually all from the United States. "Considering that total, the number of problems is relatively small," he said.

A U.S. Embassy spokesman cited three incidents, two involving murders of U.S. citizens, since Aug. 31, to explain why the United States was considering its first travel advisory for Mexico since late 1976. Such a warning would be distributed to airline offices, travel agencies and other tourism-related businesses.

"The ambassador [John Gavin] has become very concerned over what appears to be a growing degree of danger on Mexican highways," press officer John Walsh said. The advisory, if adopted, "would say at least that caution should be taken when driving on certain Mexican roads because of danger," he said.

Comments by U.S. officials and Mexican news reports indicated that the focus of the concern was Mexican police forces responsible for road safety in the areas indicated. "We're waiting to see what actions the Mexican authorities take" before deciding whether to recommend that the State Department issue the travel advisory, Walsh said. Another official said the department was reluctant to do so.

"There's always the risk" that the Mexican government would view issuing of the advisory as "an attack on Mexico," said a diplomat who asked to remain anonymous.

In one of the incidents cited by the embassy, the bodies of U.S. citizen Elisia Gonzalez, her Mexican husband Eliseo and their U.S. son Eliseo Jr. were found murdered in the desert near Caborca, 60 miles south of the Arizona border, on Sept. 11. The family, from Stockton, Calif., was driving south to Mexico City to apply for a U.S. visa for the husband. All their belongings were missing, the embassy said.

In another case, John Joseph Donovan of Bolinas, Calif., was shot to death by attackers while he was sleeping in his car south of Mazatlan on Sept. 12, the embassy reported. His wallet had been stolen.

In the third incident, five men stopped Robert Stone and his wife of Brownsville, Tex., on Highway 57 in central Mexico on Aug. 31. One of the assailants showed what appeared to be a federal police badge, and then the five tied up the couple and stole their van and all their possessions, according to the embassy account.

The stretch of Highway 57 where the Stones were assaulted -- between Matehuala and San Luis Potosi -- was one of the roadways for which the embassy was considering a warning. The others were: Highway 15 in the states of Sonora, Sinaloa and Nayarit; Highway 40 west from Durango to the Pacific Coast; and the road between Palomares and Tuxtepec in Oaxaca State.