A Belarusian artist has died in Minsk after police arrested him in a city square that has become a symbol of opposition to strongman leader Alexander Lukashenko, investigators said on Friday.
Tens of thousands have taken part in weekly protests since August when a disputed election was won by Lukashenko, who has been in power for more than two decades.
Roman Bondarenko, a 31-year-old former soldier, was arrested on Wednesday following a dispute in a Minsk square that has become a regular meeting place for the opposition.
Witnesses said unrest erupted between protesters hanging red-and-white ribbons -- the colours of the opposition -- and plainclothes police who were removing them.
He was pronounced dead on Thursday, triggering a wave of outrage among the Belarusian opposition, who believe Lukashenko's security forces are ultimately responsible.
The Investigative Committee, a body charged with investigating major crimes, said in a statement that when police arrived on the scene a 31-year-old Minsk resident had "bodily injuries and signs of alcoholic intoxication".
The statement said that the man was taken to a police station and after his condition worsened to a hospital, where he was confirmed to have alcohol in his system.
A doctor speaking on the condition of anonymity to the independent Belarusian news site Tut.by said on Friday that medical staff had found no alcohol in Bondarenko's system.
"We found nothing at all," the doctor said.
Huge crowds gathered late on Thursday to pay tribute to the artist, laying flowers and candles in the square, dubbed the "Square of Change" by the opposition after residents in surrounding housing blocks resisted attempts by security forces paint over anti-government murals in August.
Exiled opposition leader Svetlana Tikhanovskaya called for a minute's silence to take place at noon on Saturday "in every neighbourhood of every city".
"Let's do it for the sake of a man who was killed because he wanted to live in a free country," she said.
Police have detained thousands of demonstrators who have reported torture and abuse in custody, prompting international condemnation and Western sanctions.
Several people have died in the crackdown.