Belarus has carried out fresh raids against the private news agency BelaPAN and several of its employees.
The searches were carried out as part of an investigation into "organising acts that violated public order", according to the Belarusian Association of Journalists.
The association reported that the home of the agency's editor-in-chief, Irina Levchina, was searched. BelaPAN deputy editor Alexander Zaitsev also had his mobile phone, a hard drive, and a tablet seized.
The websites of the agency belapan.by and belapan.com were also not accessible since they had announced the raids on Wednesday morning.
In a statement on Telegram, the Belarusian State Investigative Committee said it had arrested three people, including Levchina and BelaPan's former director Dmitry Novozhilov.
The Committee confirmed it had opened an investigation into "mass riots and group actions that grossly violate public order".
The Belarusian Association of Journalists has called on the authorities to "immediately release" those detained.
The raids against BelaPAN -- the oldest non-state news agency in Belarus -- seem to be the latest example of the Belarusian regime's offensive against the media and the opposition.
"The Belarusian Association of Journalists is outraged by another act of severe pressure on independent media," a statement read.
"This is the second raid of the security forces on BelaPAN since the beginning of the year," they added.
Belarusian President Alexander Lukashenko has been clamping down on the unprecedented protest movement that emerged in August 2020 following his disputed re-election.
The movement gathered tens of thousands of demonstrators for months before losing momentum as its leaders were detained or forced into exile abroad.
In February, two journalists from the opposition TV channel Belsat were sentenced to two years in prison on charges of fomenting "unrest" by covering the 2020 protest.
Just last month, the Belarusian authorities blocked access to one of the main online opposition media, Nacha Niva, after having already blocked the country's main internet platform, TUT.BY, in May.
At a recent press conference, Lukashenko denied the allegations of repression and has accused his critics of trying to stage a "coup" with the help of the West.
Since last August, the Belarusian Association of journalists says that nearly 500 reporters have been detained, with around 30 in jail.
Meanwhile, the number of raids at journalists' homes has now reached 140, according to the association.
More than 100 news and media websites have been blocked and 10 print media outlets have been forced to stop publishing, they added.