Shops and businesses closed early this afternoon, again raising the level of tensions in the capital on this fifth day of Haiti's state of siege. Some opposition leaders suggested the closings were part of an organized protest that could escalate, while others said shopowners were afraid of another outburst of violence.

Most attention today, however, continued to center on conflicting reports on the number of casualties from the recent outburst of domestic violence.

The controversy intensified after the discovery yesterday of a mass grave outside the village of Poussaint, 10 miles from here, containing old bones and human skulls; there were also a few apparently fresher mounds of dirt.

The official government spokesman, Guy Mayer, described the discovery of the site, just off Haiti's main coastal road, as "bizarre" and something that "can be misinterpreted."

"Without the facts, it's hard to speculate on this," he said. "It could be a charcoal depot or a place to leave garbage."

But some antigovernment leaders said the site was widely believed to be the dumping ground for victims of the notorious security force, the Ton-Tons Macoutes.

"That is a place where they put some very poor people, as well as some people who have died clandestinely," said Gerard Gourgue, head of the Haitian Human Rights League. "It's well known. It's a place for indigents, poor people, people who die in hospitals, the people who die without identity, and people killed or assassinated by the Ton-Tons Macoutes."

Opposition leader Gregoire Eugene, head of the Social Christian Party of Haiti, said, "It's possible that many people have been buried" at the site. "It's a general opinion because this is the place where they bury people who cannot pay for a place in the general cemetery."

There were also reports -- which could not be independently confirmed -- that roaming squads of security forces have been combing slum areas of the capital at night, forcibly removing people from their homes.

The number of casualties from the disturbances that began 10 days ago has been a source of continuing confusion, with opponents of President Jean-Claude Duvalier suggesting that his regime has resorted to widespread repression in stopping the violence and maintaining his grip on power.

For the third day Duvalier, who succeeded his father, Francois (Papa Doc) Duvalier, as president for life, made a triumphant motorcade through the city, this time stopping in front of a downtown Holiday Inn where many television journalists are staying.

Asked to comment on Secretary of State George P. Shultz's call yesterday for democratic elections in Haiti, the president reportedly told the American crew, "I am president for life. What elections are you talking about?"

Mayer, the government spokesman, refused again today to put a number on the dead and injured, saying it was still too early. Other unconfirmed reports put the death toll at more than 100.

A reporter from the Chicago Tribune said yesterday that he saw about 50 bodies -- some with obvious bullet wounds -- packed in a small room at the city's morgue. Reporters who went to the morgue this morning were turned away.

This recent round of protests, which first erupted in Cap-Haitien and Gonaives, has been the most serious and widespread in the two generations of Duvalier dictatorship.

Many predicted that Duvalier's fall was imminent when the protests peaked at the end of last week, but the president apparently gained the upper hand by declaring the state of siege and appearing on television to announce that he was still in power "firm as a monkey's tail."

Since then, journalists have been told not to leave the capital, making it nearly impossible to assess the situation in the areas where the opposition was strongest.

Today, in the capital -- which has been seen as a key test of Duvalier's ability to maintain his grip -- stores that had opened in the morning began closing earlier than usual. Both Haitian and foreign observers interpreted that as a sign of increased tension.

Some shop owners reported being intimidated into closing their stores as a show of general protest against the government.

Eugene, the opposition leader, said the closings -- and the continued shutdown of the schools here -- reflected a new low-intensity phase of the protests against Duvalier.

"The schools are closed, the shops are closing. The major strategy now is passive resistance," Eugene said. "Against a violent government, the best strategy is passive resistance."

Meanwhile, prices for basic commodities in the capital were reported rising, which some here interpreted as a sign that basic food stocks were not reaching here from the provinces.