When one of the candidates challenging Mr Lukashenko in this month's presidential election tried to get into the People's Assembly, he was knocked to the ground by plain clothes officers and beaten.
Alexander Kozulin was then dragged off and taken into custody.
Outside the police station, a number of his supporters and journalists were detained, too. One newspaper photographer at the scene was beaten up by police. He received concussion and a broken nose.
Later another presidential candidate from the opposition had problems.
Alexander Milinkevich attempted to hold an election rally in the city centre. But the authorities declared it illegal and sent in the security forces: hundreds of riot police blocked off the roads and dispersed a crowd of several thousand Milenkevich supporters.
"The authorities saw that the popularity of the opposition is growing rapidly," Yaroslav Romanchuk of the United Civil Party told me. "That's why they are now trying to block the opposition from campaigning. This isn't an election. It's a sham."
I have seen two very different pictures of Belarus here this week. The first - on a TV screen, painted in pomp and ceremony, depicting Belarus as a haven of stability with a leader adored by the nation. And a second Belarus - an unofficial one, not intended for live broadcast and public consumption; a country where political rivals are beaten and detained by police.