Belarusian authorities on Sunday brought military trucks and barbed wire into central Minsk ahead of a planned opposition march, a day after police detained hundreds of women demonstrators.
The opposition movement calling for an end to the regime of authoritarian leader Alexander Lukashenko has kept up a wave of large-scale demonstrations every Sunday since his disputed win in August 9 polls.
The latest opposition protests were set to begin at 2 pm local time (1100 GMT), with opposition social media calling for demonstrators to gather in central Minsk as well as in other cities.
Belarusian opposition news sites posted video and photos of a convoy of military trucks and vehicles with rolls of barbed wire driving into the centre ahead of the demonstration.
The protest comes after riot police cracked down on peaceful women demonstrators on Saturday who were wearing shiny accessories for their so-called "Sparkly March."
They dragged protesters into vans, lifted some women off their feet and carried them.
Belarusian interior ministry spokeswoman Olga Chemodanova said Sunday morning that police had detained 415 people in Minsk and 15 in other cities for breaking rules on mass demonstrations. She said 385 had been released.
Chemodanova warned Belarusians they could face criminal charges for organising such protests.
- 'Escalation of violence' -
The number of detentions on Saturday was far higher than at a similar protest last week, prompting the opposition's Coordination Council to warn of a "new phase in the escalation of violence against peaceful protesters."
Among those detained was one of the most prominent faces of the protest movement, 73-year-old activist Nina Baginskaya, although she was later released.
The aggressive police tactics prompted an opposition Telegram channel, Nexta, which has more than 2 million subscribers, to publish what it said was a list of the names and ranks of more than 1,000 police.
Protesters have sought to expose the identity of police who appear at demonstrations in plain clothes or in uniforms without insignia or name badges, trying to pull off their masks and balaclavas.
Opposition leader Svetlana Tikhanovskaya, who claimed victory over Lukashenko in the polls and has taken shelter in Lithuania, on Saturday said Belarusians were ready to strip police obeying "criminal orders" of anonymity.
A female anchor on state television channel Belarus 1 criticised the women protesters on Saturday evening, asking: "How did these women get so aggressive? After all nature intended them to guard their hearth."
The broadcast made no mention of police detentions.
Lukashenko has dismissed opposition calls for his resignation and sought help from Russia's President Vladimir Putin, who has promised law enforcement backup if needed and a $1.5 billion loan.
Tikhanovskaya is set to meet European Union foreign ministers in Brussels on Monday as the EU prepares sanctions against those it blames for rigging the election and the regime's violent crackdown on protesters.
Authorities have jailed many of Tikhanovskaya's allies who formed the leadership of the Coordination Council or driven them out of the country.
One of her campaign partners, Maria Kolesnikova, has been imprisoned and charged with undermining national security.