According to editor-in-chief Marina Zolotova, she and several of the employees on the site Tut.by have also had their homes searched by employees linked to a state body for financial investigations.
- Representatives from the security service also came to the editorial office, she says.
According to the Belarusian Association of Journalists, a total of 16 journalists were detained on Tuesday.
The State Investigation Committee's Department of Financial Investigations, which is behind the crackdown, is a powerful body that has previously cracked down on Belarus' opposition.
The authority states that Tut.by is the subject of an investigation into suspected tax evasion.
"Deliberate attack"
The government withdrew the site's official media status in the autumn, when authorities cracked down on widespread protests against the rule of authoritarian President Alexander Lukashenko.
The media crackdown has prompted Belarus' opposition leader Svetlana Tichanovskaya, who is currently in exile in Lithuania, to urge the international community to show its support for the country's media.
"This is a deliberate attack on our journalists and our media, and they need legal protection and are urgently relocated to new premises," the opposition leader wrote on Twitter.
Hunger strikes
The situation for journalists in the country has deteriorated sharply since the protests began last year.
Last week, two foreign journalists were each sentenced to 20 years in prison for reporting on the protests in the country. Both journalists have now launched a hunger strike to protest the verdicts.