KYIV/MOSCOW (Reuters) - Belarusian police used stun grenades against protesters on Sunday as tens of thousands of people headed towards Independence Palace in the capital Minsk demanding that President Alexander Lukashenko resign.
Protesters carrying the red-and-white flags of the Belarusian opposition movement scattered as loud bangs and flashes lit up the city's streets after nightfall, videos showed.
The police action came hours before the expiration of an ultimatum set by the opposition: Lukashenko must resign by midnight or face a national strike.
Explosions and white smoke filled residential areas as people hid behind vehicles and ran from police, the videos, shared online by news organisations, showed. The videos could not be immediately verified by Reuters.
Law enforcement confirmed that riot control weapons had been used and detentions had taken place, the Russian news agencies TASS and RIA reported.
Human rights group Vesna-96 said 128 people had been detained so far on Sunday, and shared a list of their names online.
An interior ministry spokeswoman said it was too early to say how many people had been injured or detained. "We will only know by the morning if there are any injured people," Olga Chemodanova was cited by RIA as saying.
Earlier on Sunday, crowds streamed through the capital shouting "strike", waving flags and beating drums on the 11th straight weekend of mass protests since a disputed election plunged the country into turmoil.
Twelve metro stations were closed, helmeted riot police patrolled the streets and mobile internet services were disrupted in Minsk. Two journalists were detained ahead of the protest, a local journalists' association said.
Tens of people were detained and security forces used tear gas in the western town of Lida, the Russian news agency RIA quoted the regional branch of the interior ministry as saying.
Lukashenko has ruled Belarus for more than a quarter of a century and has shown little inclination to quit, buoyed by loans and the offer of military support from traditional ally Russia.
The president's main opponents have been jailed or fled into exile following the Aug. 9 election, which Lukashenko's opponents accuse him of rigging to win a sixth straight term. He denies electoral fraud.
Sviatlana Tsikhanouskaya, his main electoral challenger, has led calls from exile for a national strike to begin on Monday if Lukashenko refuses to release all political prisoners and resign to make way for a new election.
"Today at 23:59 the term of the People's Ultimatum will expire, and if the demands are not met, the Belarusians will start a national strike," she said in statement.
Lukashenko has signalled that he would ignore the ultimatum.
The United States, the European Union, Britain and Canada have imposed sanctions against a string of senior officials in Belarus accused of fraud and human rights abuses in the wake of the presidential election.
Lukashenko has accused Western countries of meddling in the internal affairs of Belarus and trying to instigate a violent uprising against him.
In a call with U.S. Secretary of State Mike Pompeo on Saturday, he said Belarus and Russia were ready to respond jointly to external threats, Belarusian state television reported.