Tens of 1000’s of persons are reportedly marching within the capital Minsk and different cities, within the newest of a number of weeks of mass protest in opposition to President Alexander Lukashenko.
Large numbers of police have been deployed, blocking key areas.
Police mentioned that they had arrested about 250 individuals forward of the demonstration, dubbed the March of Heroes.
The protests have been triggered by a broadly disputed election a month in the past and subsequent brutal police crackdown.
Demonstrators need Mr Lukashenko to resign after alleging widespread ballot-rigging.
But the Belarusian chief – in energy for 26 years – has denied the allegations and accuses Western nations of interfering.
The 66-year-old has promised to defend Belarus.
Most opposition leaders at the moment are underneath arrest or in exile.
It is the fifth successive Sunday of mass protests, with about 100,000 rallying every week.
Eyewitnesses mentioned the centre of Minsk was flooded with individuals. They are marching in direction of the elite residential space of Drozdy, the place the nation’s prime officers together with President Lukashenko dwell, however roads are blocked by police.
Rallies are additionally being held in Brest, Gomel, Mogilyev and different cities.
However, the Interior Ministry mentioned that as of 15:00 native time (12:00 GMT) the protests concerned not more than 3,000 individuals throughout the nation.
The ministry mentioned arrests have been made in numerous districts of the capital, and that these detained have been carrying flags and placards “of an insulting nature”.
Protests have been triggered by elections on 9 August, wherein Mr Lukashenko was handed an amazing victory amid widespread studies of vote-rigging.
Violent clashes on a number of nights following the ballot led to 1000’s of arrests, and particulars emerged of extreme beatings by police and overcrowding in detention centres.
This produced a brand new wave of demonstrations, with weekend rallies drawing tens of 1000’s.
Mr Lukashenko has mentioned he could set up nearer ties with Russia, his fundamental ally.
On no less than two events up to now few weeks, he has been photographed close to his residence in Minsk carrying a gun and being surrounded by his closely armed safety personnel.