KYIV (Reuters) - Thousands of people carrying candles and flowers gathered in Minsk on Thursday to mourn the death of a 31-year-old anti-government protester who they say was badly beaten by Belarusian security forces and died in hospital.Witnesses say Roman Bondarenko was detained after scuffling with people in plain clothes who had come to a playground to remove red-and-white ribbons that represent the protest movement against veteran President Alexander Lukashenko. The interior ministry denied responsibility for Bondarenko’s death, saying he was killed due to a scuffle with civilians. The death is the latest flashpoint in months of mass protests against Lukashenko following a disputed presidential election in August. The opposition says Lukashenko rigged the vote to secure a sixth successive term.