The personal data of 2,000 Belarusian police officers was leaked by anonymous hackers in retaliation for a crackdown on demonstrations against president Alexander Lukashenko, as more than 100,000 people marched through Minsk for the sixth straight weekend.
Many walked in a column stretching back several kilometres, clad in opposition red-and-white colours and chanting “go away” as riot police patrolled the streets, a witness said.
At least 196 people were detained across the country on Sunday, human rights group Spring-96 said.
Russia’s Tass news agency quoted police as saying at least 10 people had been detained, while videos shared by local media showed security forces in helmets and masks hauling protesters off the streets.
Hundreds of soldiers blocked off the centre of the capital, deploying water cannons and armoured personnel carriers and erecting barbed-wire barriers.
But in a statement distributed by the opposition news channel Nexta Live on the messaging app Telegram, the hackers said: “As the arrests continue, we will continue to publish data on a massive scale.
“No one will remain anonymous, even under a balaclava.”
The first batch of 1,000 names was released on Saturday and widely distributed on Telegram channels.
The second batch of more than 1,000 names was released on Sunday evening, targeting officers in the western city of Brest where the hackers said the police had been particularly heavy-handed.
The government said it would find and punish those responsible for leaking the data.
“The forces, means and technologies at the disposal of the internal affairs bodies make it possible to identify and prosecute the overwhelming majority of those guilty of leaking personal data on the internet,” said Olga Chemodanova, a spokesperson for the Ministry of Internal Affairs.
The loyalty of the security forces is crucial to Mr Lukashenko’s ability to cling on to power following August’s presidential election, in which he claimed a landslide victory but his opponents and some poll workers say was rigged to hand the former Soviet collective farm boss a sixth term.
Security forces with their faces often obscured by masks, balaclavas or riot helmets have detained thousands of people to tackle a wave of rallies and strikes aimed at keeping up the pressure on the Belarusian leader to quit after 26 years in power.
Some protesters have torn off the masks of several officers.
The government said 390 women were detained for taking part in a protest on Saturday, but most have now been released.
The president has rejected suggestions of dialogue with the protesters.
The European Union vowed to impose sanctions on Mr Lukashenko’s government for alleged election fraud and human rights abuses weeks ago, but it looks likely to miss its own Monday deadline for action.
Minsk reacted angrily on Saturday to reports that Sviatlana Tsikhanouskaya, the leading opposition candidate in last month’s election, could soon meet EU foreign ministers.
Russian foreign ministry spokesperson Maria Zakharova also criticised the EU for inviting Ms Tsikhanouskaya to the ministerial meeting and for considering sanctions against Minsk, saying Brussels was trying to “rock the boat” in Belarus.
Additional reporting by agencies