Tens of thousands of people have been marching in the capital Minsk and other cities, in the latest of several weeks of mass protest against President Alexander Lukashenko, BBC reported.
Belarus: 400 protesters detained during 'March of Heroes'
STEPANAKERT, SEPTEMBER 14, ARTSAKHPRESS: Large numbers of police have been deployed, blocking key areas.
Police said they arrested about 400 people ahead of and during the protests, dubbed the March of Heroes.
The protests have been triggered by a widely disputed election a month ago and subsequent brutal police crackdown.
Demonstrators want Mr Lukashenko to resign after alleging widespread ballot-rigging.
But the Belarusian leader - in power 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 are now under arrest or in exile. It is the fifth successive Sunday of mass protests, with about 100,000 rallying each week, the source said.