MOSCOW (AP) _ A car tried to ram Princess Anne's limousine as it made its way to Moscow airport, but fled after police fired at it, police said Tuesday. A palace spokesman denied the report.

Princess Anne did not comment on the alleged weekend incident as she continued a 10-day visit to the former Soviet Union.

She cantered on a stallion across the vast Mongolian steppe on Tuesday, marveling at the uninterrupted view.

Wearing denim culottes and cowboy boots, she took time out from her ride to confide to nomadic herdsman Dendiviin Janshev, ''Just being able to ride and ride and ride. There is a sense of space that is different from anywhere else.''

Anne arrived Saturday and will visit the former Soviet republics of Russia, Uzbekistan and Kazakhstan as well as Mongolia on her 10-day trip. She is accompanied by her husband, navy Cmdr. Tim Laurence.

The alleged ramming attempt was first reported Tuesday by the newspaper Commersant Daily, whose account was confirmed by police.

Police said that an unidentified driver sped away after officers fired at his car. The incident Saturday probably was reckless driving and not an assassination attempt, police spokesman Stanislav Yablochkin said.

No one was hurt.

But a Buckingham Palace spokesman with the party in Mongolia denied that any ramming attempt was made and said neither he nor the princess was aware of shots being fired. He spoke on the customary condition of anonymity.

''It appears the driver attempted to cross the royal party convoy. ... At no stage was an attempt made to ram the Princess Royal's car. That simply didn't happen,'' he said.

The newspaper account said that Anne's limousine was traveling on a highway leading from the center of Moscow to Sheremetyevo-2 international airport.

Outside city limits, a light beige Zhiguli sedan sped into the right lane alongside police escort cars. Police loudspeakers ordered the car to move away, but it tried to ram Anne's vehicle, prompting a burst of police gunfire.

The sedan, with only a male driver visible inside, quickly veered away and sped along the highway that leads to St. Petersburg.

Police, under orders to stay with the limousine, could not chase the sedan and neither car nor driver has been found.