Polish officials accused Belarus of shifting tactics to encourage migrants to cross the border into Poland, as new attempts to breach the frontier were reported.
Polish Defense Minister Mariusz Blaszczak said on November 20 that he expected the border showdown to be long drawn out while Belarus said the situation remained "tense."
"We have to prepare for the fact that this problem will continue for months. I have no doubt that that will be the case," Blaszczak told RMF FM radio.
With thousands of people either camped out on the border and waiting elsewhere in warehouse-like conditions, the European Union has accused Belarus of fomenting the crisis by bringing in people -- mostly from the Middle East -- and directing them to the border with promises of making into the European Union.
Belarus has denied the claim, despite mounting evidence that Belarusian border guards were doing some coordination with migrants.
The new attempts occurred late on November 19 amid a drop in the number of people that have been trying to force their way into Poland.
"The foreigners were aggressive. They threw rocks and fireworks and used tear gas," a police statement said, adding that the largest group consisted of 200 foreigners.
Polish police said that during one crossing attempt near the village of Starzyna, Belarusian servicemen threw stones towards Polish border guards, policemen and soldiers, resulting in police cars being damaged.
The EU accuses Belarusian ruler Alyaksandr Lukashenka of flying in migrants and funneling them to the borders of member states Poland, Latvia, and Lithuania to retaliate for sanctions the bloc imposed over a sweeping crackdown since last year's disputed presidential election.
Speaking to the BBC on November 19, Lukashenka said it was "absolutely possible" his forces had helped people cross into the EU but denied inviting thousands of mostly Middle Eastern migrants to Belarus in order to provoke a border crisis.
Polish officials said they recorded a total of 195 attempts to cross the border illegally on November 19, down from 250 on November 18 and 501 the day before, though Warsaw warned that the migrant crisis was far from over.
There is no question that these attacks are directed by Belarusian services," Blaszczak said.
Polish Prime Minister Mateusz Morawiecki will visit Lithuania, Latvia and Estonia on November 21 to discuss the crisis, a government spokesman said on November 20.