As international observers proclaimed a leftist priest the winner of Haiti's first democratic elections, a police attack on a celebration rally renewed fears of a backlash by right-wing thugs.

The Rev. Jean-Bertrand Aristide, a fiery champion of the poor, won as much as 70 percent of the vote in Sunday's elections, according to projections by the 800 foreign observers. Final results were not expected until late today."We fully respect him as the apparent president-elect of Haiti and look forward to closely working with his government," said Bernard W. Aronson, the assistant U.S. secretary of state for inter-American affairs.

With slightly more than 1 percent of the estimated 2 million votes counted, Aristide had 70.6 percent; former World Bank official Marc Bazin 12.6 percent; agronomist Louis Dejoie Jr. 6.9 percent; and evangelical preacher Sylvio Claude 2.7 percent. Seven other candidates were in the race.

Bazin had made no public comment by

late Monday. Dejoie conceeded defeat.

Observers from the United Nations and the Organization of American States said the vote was orderly and without fraud, despite delays and some irregularities at voting stations.

About 70 percent of the registered voters cast ballots for president, a 110-member National Assembly and local officials.

Tens of thousands of Haitians poured into the streets Monday morning in celebration of Aristide's presumed victory.

But the party ended at midday. Police wearing gas masks fired into a crowd celebrating outside St. Jean Bosco Roman Catholic Church, killing a pregnant 44-year-old woman, then running her over in a blue pickup truck, witnesses said.

Assassins attacked the church in September 1988 as Aristide was saying Mass, killing 12 people and wounding 70. Aristide escaped and went into hiding.

An army statement denied responsibility for Monday's shootings, saying police had fired into the air to disperse demonstrators threatening to lynch an unidentified man. Police in Haiti are under the authority of the army.

The capital was nearly deserted as Haitians fled indoors, fearing more violence from holdovers of the 29-year Duvalier family regime, which was ousted in 1986 when Jean-Claude "Baby Doc" Duvalier fled into exile.

The only other time Haitians had a chance to freely choose their leader, in November 1987, 34 voters were shot and hacked to death at polling stations by thugs supported by the army. The vote was canceled.