Outgoing President Robert Kocharian, meanwhile, warned that authorities were losing patience with the continuing protests.

Officials said Prime Minister Serge Sarkisian won the vote outright, but supporters of opposition candidate Levon Ter-Petrosian have rejected that result and have tried to stage round-the-clock demonstrations in an effort to force a new vote.

Hundreds of protesters have been staying overnight in tents on a central square in Yerevan. On Tuesday, in the largest such gathering to date, tens of thousands rallied in one section of the city calling on election authorities to annul the Feb. 19 vote and to release detained activists.

"For my first order, I award Serge Sarkisian a military cross of honor," Ter-Petrosian told the roaring crowd. "Thanks to him, the number of people coming to our meetings has doubled _ people left his meeting to come to ours."

On another square just a few hundred meters (yards) away, as many as 100,000 people gathered in support of Sarkisian, who said he was prepared for discussions with opposition leaders, but also warned of potential violence.

"Now is not the time to gather stones; just the opposite, it is the time to throw off the stones from our shoulders and look to the future with optimism," he said.

Police officials and opposition groups said Tuesday that more people, including several activists, were detained on various charges, but it was unclear precisely how many. A total of 10 people, many of them opposition supporters, were in city jails on Tuesday and at least half had been charged with public disorder and similar charges.

Three opposition activists were released late Tuesday.

Tensions are mounting as pressure grows on the government in the poor Caucasus nation to dispel any doubts about the vote and keep the protests from gaining momentum. Western election observers have said there were concerns about the vote count, but issued a generally positive assessment.

On Monday, a businessman and leading backer of Ter-Petrosian was detained by police and they said guns, knives, bulletproof vests and ammunition were seized from a three-car convoy that a pro-Ter-Petrosian lawmaker was driving in. Authorities have also arrested two Ter-Petrosian supporters who held high-level posts when he was Armenia's president in the 1990s.

In an interview with state television, Kocharian signaled that the government was running out of patience with the demonstrators.

"I ask: is there a limit to our patience? How many more days will this continue?" he said. "It's time for people to calm down, come to their senses."

Also Tuesday. the ex-Soviet republic's top security agency issued a statement saying opposition supporters were plotting to seize a television broadcast tower _ a charge immediately denied.

"It's another political attempt of psychological pressure. There is nothing to comment on," said Arman Musinian, a spokesman for Ter-Petrosian.

The standoff has raised concerns about stability in the volatile, strategic country at the junction of the energy-rich Caspian Sea region and southern Europe, with Iran and Russia _ which has close ties and maintains a military base in Armenia _ nearby.