© Reuters / BelaPANFILE PHOTO: Belarusian police disperse a rally in Gomel.
Police said they resorted to using the equipment because "some people acted inadequately." The flashbangs were fired only as warning shots, a spokesman insisted.
Videos from the scene showed a large group of demonstrators advancing on officers in balaclavas and full riot gear, who were blocking the street.
When the two groups came face to face, the police fired stun devices into the air and sprayed tear gas at the protesters.
After a brief shoving match the crowd retreated, shouting "fascists," while the law enforcers were filmed arresting at least one man.
Gomel, which is populated by more than 500,000 people, is one of many cities in Belarus where protests took place on Sunday. The largest rally was staged the capital Minsk, where thousands took to the streets again to demand Lukashenko's resignation and a new fair election.
People have been protesting across the country since the presidential election on August 9, which the opposition insists was rigged. The demonstrations have been marred by mass arrests and accusations of police brutality.
Around 200 people were detained on Sunday as the Belarusian capital, Minsk, and other cities hosted rallies, during which the opposition held a "people's inauguration" of exiled presidential candidate Svetlana Tikhanovskaya.
The action was called in response to the secret induction staged by long-time President Alexander Lukashenko earlier this week. Tikhanovskaya won't be attending the protest, as she fled Belarus for Lithuania after the August 9 election, which the opposition insists was rigged.
Thousands marched along Independence Avenue in Minsk, despite security forces thoroughly preparing for the unsanctioned event and urging people to stay at home. Mobile internet speed was reduced in the capital. A local mobile operator said it was ordered to do so by the government. It was likely done to complicate communication among demonstrators.
The city's largest squares were blocked off, with seven metro stations in the center also shut down. A convoy of armored vehicles was also spotted outside Lukashenko's heavily guarded residence.
Music was played from loudspeakers along the route of the march to drown out the chants of the demonstrators, calling for Lukashenko's immediate resignation and a new, fair election.
The protests in Belarus have been marred by mass arrests from the very start, with thousands of anti-government demonstrators detained in the weeks since the election. Police have also been accused of using excessive force against demonstrators and mistreating detainees. Three protesters have been killed during the unrest, according to official data, with hundreds, including many officers, wounded.
Comment: It would appear that Lukashenko won the election fairly, and those protesting for change of any kind aren't doing their cause any favors following leaders that are cavorting with known regime change enthusiasts nor those attempting to seize power undemocratically: