Riot police charged protesters near the presidential palace, firing pepper spray and wielding batons, and dozens of arrests were made.
Protesters are seeking the resignation of the long-time president.
They accuse the authorities of rigging his re-election just over a month ago, sparking deadly mass unrest.
At least four people have died and hundreds have been injured since then, as the government tried to stamp out dissent.
A number of opposition figures have fled the country, On Saturday, activist Olga Kovalkova became the latest to say she had taken refuge in neighbouring Poland amid threats of imprisonment.
Mr Lukashenko, in power since 1994, has accused Western nations of interfering.
Protesters, human rights activists and observers say riot police are brutally suppressing peaceful marches.
The former Soviet republic borders Russia, on which it depends heavily for energy and with which it historically has close ties, as well as Ukraine and EU states.
Sunday has become the key day for street demonstrations since the rallies began.
In recent days the security forces – dressed all in black with balaclavas over their faces – targeted university students as they returned from their holidays, dragging some from the streets and university buildings into unmarked minivans.
Video footage on Sunday shows men in plain clothes beating peaceful protesters with batons.
A Belarusian human rights group said more than 150 people had been detained in Minsk.
One protester in Minsk, who gave her name as Lyudmila, told BBC News earlier that the demonstrators were undeterred by the security forces.
“We are definitely not ready to get back to the life we had for many years now,” she said.
“We finally feel like we matter because we’ve been living in apathy for way too long and now we just have this feeling of solidarity and we actually think that – well, I feel personally that – changes already are happening so that’s definitely not the time to give up.”
Protests have also been reported in other Belarusian cities and towns including Grodno, Mogilev and Gomel.
SOURCE: BBC NEWS