Police detained eight journalists from Belarusian news outlets on Tuesday on charges of taking part in an unsanctioned demonstration.
They could receive fines or jail sentences of up to 15 days, if charged and convicted.
“We are witnessing the lawless action of law enforcement agencies, which are muzzling journalists without bothering about methods,” said Olga Loiko, a journalist with Belarus’s popular online news outlet tut.by.
As it tries to quell weeks of anti-government protests prompted by official results that gave President Alexander Lukashenko a sixth term with 80% of the vote, his government has also revoked the accreditation of many Belarusian journalists and deported some foreign journalists.
Two Moscow-based Associated Press journalists who were covering the protests were deported to Russia on Saturday.
In addition, the AP’s Belarusian journalists were told by the government that their press credentials had been revoked.
American and European Union officials have strongly condemned the targeting of media in Belarus.
During Tuesday’s protest, hundreds of students marched across the city, chanting for Mr Lukashenko to “Go away!” as they continued a fourth straight week of mass post-election protests.
The Interior Ministry said 128 people were detained across the country on Tuesday for taking part in unsanctioned demonstrations, including 95 in the capital Minsk.
It said on Wednesday that 39 of the detainees remained in custody pending court hearings.
More than 100 students from the Minsk State Linguistics University formed a human chain to protest over Tuesday’s detentions of students and professors.
The Viasna human rights centre said police detained at least eight participants in Wednesday’s protest.
Mr Lukashenko, who has run the ex-Soviet nation of 9.5 million with an iron fist for 26 years, has dismissed protesters as Western puppets.
During the first few days of post-election protests, police detained nearly 7,000 people and beat hundreds, drawing international outrage.
The government has since avoided large-scale violence and sought to end the protests with threats, selective detention of protesters and prosecution of activists.
The US and the EU have criticised the August 9 presidential election as neither free nor fair and urged Belarusian authorities to engage in a dialogue with the opposition, a demand Mr Lukashenko rejected.
Belarusian prosecutors have opened a criminal probe of the opposition’s Co-ordination Council set up after the election to try to negotiate a transition of power.
Last week, two of its members were given 10-day jail sentences on charges of staging unsanctioned protests, and several others were summoned for questioning.
Pavel Latushko, a former minister of culture and ambassador to France who joined the council, left for Poland after facing threats and being questioned.
His departure came after the Belarusian president warned that Mr Latushko had crossed a “red line” and would face prosecution.
The Co-ordination Council said Mr Latushko planned to return to Belarus after a few days.
Facing Western pressure, Mr Lukashenko has vowed to cement ties with Russia, which has a union treaty with Belarus envisaging close political, economic and military ties.
Russian President Vladimir Putin said last week he stands ready to send police to Belarus at Mr Lukashenko’s request if the demonstrations turn violent, but added that there was no need for that yet.
Belarusian foreign minister Vladimir Makei thanked Russia for supporting the Belarusian government in the face of what he described as protests orchestrated from abroad.
Russian foreign minister Sergey Lavrov criticised what he described as “destructive” Western criticism of the Belarusian authorities.
Asked if Moscow plans to have contacts with the Belarusian opposition, Mr Lavrov said that would not happen until the Co-ordination Council formulates a platform that conforms with Belarusian law.
He noted that some council members have spoken against close ties with Russia.
