Protests against Russia's invasion of Ukraine broke out in Minsk and other cities as Belarusians cast ballots in a referendum on constitutional changes to tighten Alyaksandr Lukashenka's grip on power.
Video posted on social media showed several people in different places around the country being detained on February 27 as they held various demonstrations against the invasion.
More than 300 people were detained, mostly in Minsk, according to the Vyasna human rights group, which listed the names of the people arrested on its website.
The referendum would change the constitution to allow Lukashenka, 67, to rule until 2035, offer him a new lever of power, and abolish a section of the document defining Belarus as a "nuclear-free zone," possibly paving the way for the return of Russian nuclear weapons to Belarus.
Speaking at a polling station on February 27, Lukashenka said that he could ask Russia to return nuclear weapons to Belarus.
"If you (the West) transfer nuclear weapons to Poland or Lithuania, to our borders, then I will turn to [Russian President Vladimir] Putin to return the nuclear weapons that I gave away without any conditions," Lukashenka said.
Opposition leader Svyatlana Tsikhanouskaya said the referendum was Lukashenka's attempt to strengthen his grip on power and called on Belarusians to use the vote to protest the war against Ukraine.
"All over the country, Belarusians gather to protest against the war in Ukraine, Belarus's involvement in it, against the Lukashenka regime," Tsikhanouskaya said on Twitter.
Lukashenka proposed the constitutional changes following domestic and international backlash over his violent crackdown on dissent after the August 2020 presidential election that he claims gave him a sixth consecutive term. The opposition says the vote was rigged.
The Crisis In Belarus
Read our coverage as Belarusian strongman Alyaksandr Lukashenka continues his brutal crackdown on NGOs, activists, and independent media following the August 2020 presidential election.
One person sent a picture to RFE/RL of a ballot they said they submitted.
Both yes and no were marked on the ballot along with a message to free blogger and RFE/RL consultant Ihar Losik, who in December was handed a 15-year prison sentence after being accused of using his popular Telegram channel to "prepare to disrupt public order."
Deemed illegitimate by much of the West, Lukashenka now depends on support from Putin, who has exploited that weakness to extract further concessions that the Kremlin hopes will be cemented under a final union state.
Lukashenka, a former communist-era collective-farm manager, has a history of tampering with Belarus's constitution.
In 1996, he significantly expanded his own powers as president and reduced the powers of parliament, while in 2004 he lifted restrictions on the number of presidential terms that can be served.
In 2016, Lukashenka first mentioned a possible third round of constitutional changes, announcing the need to "create a group of wise men, lawyers who will analyze our fundamental law."
That talk largely vanished until the aftermath of the disputed 2020 presidential election, when tens of thousands took to the streets in some of the biggest protests in Belarus's post-Soviet history.
Lukashenka eventually unveiled his plans for a referendum on the changes that give more powers to the All-Belarus People's Assembly, a periodic gathering of loyalists that currently has no governing status under the law. He said it could provide a "safety net" in case "the wrong people come to power, and they have different views."
The revamped All-Belarus People's Assembly, if the changes are approved as expected, would act as a parallel structure next to parliament, holding wide-ranging powers to approve foreign, security, and economic policy. It would also be able to propose changes to the constitution, draft laws, and select members of the Central Election Commission and judges of the top courts.
According to the proposed amendments, a sitting president automatically becomes a delegate of the 1,200-seat assembly and may chair it if elected by other delegates.
The proposed changes also would give Lukashenka immunity from prosecution and put in place a limit of two terms in office, each for five years. However, the restrictions would only apply going forward, meaning Lukashenka could rule until he is 81 years old.
The amendments would also prohibit anyone who temporarily left the country in the last 20 years from becoming president, a change aimed directly at opposition members, many of whom were forced into exile to avoid political persecution.