Thousands of people have gathered in a square near Belarus’ main government building for a rally to support President Alexander Lukashenko.
Opposition supporters whose protests have convulsed the country for a week are meanwhile aiming to hold a major march in the capital.
Protests began late on August 9 at the closing of presidential elections.
Official results say the authoritarian Mr Lukashenko, in office since 1994, won a sixth term in a landslide with about 80% of the vote.
Protesters claim the election was a sham and allege results were manipulated.
About 7,000 people were arrested over several days of protests, which police tried to put down with clubs, rubber bullets and flash grenades.
Many detainees were later released, complaining of brutality from police while in custody and showing extensive bruises.
As Mr Lukashenko’s supporters waited for his appearance at the Sunday rally, many chanted his nickname of “Batka”, or father, and “Maidan won’t take place”, referring to the months of protest in Ukraine in 2013-14 that drove then-president Viktor Yanukovych to flee the country.
Belarus’ declining economy and Mr Lukashenko’s dismissal of the coronavirus pandemic as “psychosis” are among the factors that galvanised the largest and most sustained protests the country has seen.
