Poland's Defence Ministry said its soldiers and other border forces were attacked with stones and other objects and that Belarusian forces tried to destroy fencing along the common border.
Polish forces have fired tear gas and deployed water cannons against stone-throwing migrants trying to cross the border from Belarus.
"Migrants attacked our soldiers and officers with rocks and are trying to destroy the fence and cross into Poland," Poland's Defence Ministry said on Tuesday, tweeting a video showing apparent clashes at the border.
"Our forces used tear gas to quell the migrants' aggression."
Polish police said an officer was seriously injured with a likely skull fracture in the clashes, and said stun grenades and tear gas canisters had been thrown back at officers.
One of the 🇵🇱soldiers was hit with a stone in the face during today's migrant attack. He was given medical help. His life and health are not in danger. https://t.co/SfWIY4wxjd— Poland MOD 🇵🇱 (@Poland_MOD) November 16, 2021
Russia condemned Poland's use of tear gas and water cannons against the migrants, with Foreign Minister Sergey Lavrov calling it "absolutely unacceptable".
Polish border guards estimate up to 4,000 migrants are currently camped out along the border between Poland and Belarus in increasingly dire conditions and freezing temperatures.
Growing sanctions list
"We cannot let this so-called problem lead to heated confrontation," Lukashenko told a government meeting on Tuesday.
"The main thing now is to protect our country and our people, and not to allow clashes," he added, according to state news agency Belta.
The Belarusian leader discussed the crisis with Germany's Angela Merkel on Monday and he and Merkel agreed the standoff should be defused.
Merkel's office said the pair discussed bringing humanitarian aid to the migrants, whose number includes many young children.
"We were of the united opinion that nobody needs escalation, not the EU, or Belarus," Lukashenko said.
But he said he had "differing" views with Merkel on how the migrants got to Belarus, with the West saying Minsk had brought them there as revenge for sanctions.
EU foreign ministers on Monday agreed that existing sanctions targeting Lukashenko's regime will be expanded to include individuals or companies found to have encouraged border crossings.
The US has also vowed to expand its sanctions on Belarus.