The Belarusian opposition is planning to push for political prisoners to be freed in the coming days, after the disputed re-election of President Alexander Lukashenko unleashed mass demonstrations against his rule.
Maria Kolesnikova said criminal charges would be filed Monday over the deaths of two protesters and the violent response of police and the security forces against protesters and prisoners.
Kolesnikova is the former campaign chief of Viktor Babariko, an opposition candidate who was jailed before the August 9 election.
Addressing protesters in Minsk on Sunday, she read the names of some of the people who have been detained - including Babariko and another jailed election challenger, Sergei Tikhanovsky. Tikhanovsky's wife Svetlana ran in the election in his place.
Some 4,000 people are still detained after bloody protests that started last week after the election, Kolesnikova said. More than 2,000 have been released. According to Belarusian media reports, the whereabouts of around 80 of those who were arrested is unknown.
She repeated calls for the resignation of Lukashenko, who has rejected allegations of vote-rigging in last Sunday's election that handed him a sixth landslide victory in a row, extending his 26 years in power of the former Soviet republic.
"The 26-year-long nightmare must end," she said.
"There will be no peace until those currently in power have resigned and Belarus is a free country," Kolesnikova told protesters.
Lukashenko supporters
Earlier, Lukashenko had appeared before supporters and emphasized that he had no plans to step down.
Footage shown by local broadcasters showed thousands of people thronging Minsk's Independence Square, with some shouting "For Lukashenko" and others wearing t-shirts saying "We agree."
Local media reported that some government employees had been pressured to join the protests, while photos of busloads of protesters being brought to the capital were circulated on social media.
Independent observers estimated 10,000 participants, while state news agency BelTA reported 50,000. Hundreds of thousands were estimated to have turned out to protest against Lukashenko.
With a win of more than 80% of the votes, there could be no electoral fraud, Lukashenko told the rally of supporters in Minsk, according to BelTA. "I stand here as before God."
At the same time, he rejected calls for fresh elections. "Lithuania, Poland and Ukraine are ordering us to hold new elections," he said. "If we let them lead us by the nose, then we'll get held back. Then we perish as a nation."
The electoral commission gave Lukashenko 80.1% of the vote, but many ordinary Belarusians have serious doubts about this.
A lot of evidence suggesting massive fraud has been shared on social media. Some reports spoke of of pre-completed ballot papers, for example, while others reported incorrect documentation.
"Country must be protected"
Against the background of the street protests, Lukashenko asked his followers for help on Sunday: "Dear friends, I have called you here to protect me." For the first time in a quarter of a century, the country, families, children and women must be protected, he added.
"For the first time in my life I am on my knees in front of you," he said in his speech.
Long-time ally Russia confirmed its readiness to "provide the necessary assistance in solving problems that arise," in a telephone call between Lukashenko and his Russian counterpart Vladimir Putin on Sunday, the Kremlin said in a statement.
The statement refers to a treaty between the two neighbouring countries, which also regulates "collective security."
The two leaders had already spoken by telephone on Saturday, when Lukashenko spoke of military aid from Moscow, but state media backtracked on this claim afterwards and the Kremlin made no mention of it.
Belarusian analyst Artyom Shraibman considers Russian military intervention in support of Lukashenko extremely unlikely. "Russia does not use armed forces to save regimes that have fallen," he said on Sunday night.
Also on Sunday, hundreds of people paid their last respects in the Belarusian city of Gomel to a young man who was arrested during an anti-Lukashenko protest and who later died in hospital.
People laid flowers and lit candles, as seen in pictures shared on the Telegram messenger service. Balloons were attached to photos of the 25-year-old. Many stood quietly in front of them.
His mother blames the police for the death of her son, who had heart disease. He was arrested on 9 August - when the widely disputed presidential election was held - on the way to see his girlfriend, and died in police custody in the hospital.
The police only confirmed this on Wednesday and said that a forensic investigation would clarify the cause of death.
On Saturday there was a funeral service for another killed demonstrator in Minsk. According to the authorities, an explosive device exploded in his hand. Many doubt this version of events.
