The Polish Border Guard told CNN that Saturday's figure of of 739 attempted crossings was the most so far for a single day. They're the latest in a weeks-long migration crisis at the border, for which Poland imposed a state of emergency last month.
Approximately 16,000 attempts to illegally cross the Polish-Belarusian border have been stopped since August, Poland's border agency has said. Of those, 5,000 took place in October.
The crossing could become increasingly dangerous as the seasons change. At least four people died on the border between Poland and Belarus in August; three people were found dead on the Polish side of the border after suffering from hypothermia, according to Polish authorities, and a fourth was found dead in Belarus, one meter from the border, Belarusian state agency Belta reported.
Many of those arriving at Eastern European borders are from Afghanistan and Iraq.
Relations between Belarus and its neighbors are growing increasingly tense over the border situation. In August, the prime ministers of Poland, Latvia and Lithuania accused Belarusian President Alexander Lukashenko of creating the crisis by driving migrants toward the European Union.
On Friday, Poland also summoned Belarusian charge d'affaires Alyaksandr Czasnouski amid allegations of bullets being fired at Polish soldiers stationed along the border. Czasnouski has told press that "the information about the shots is not true."
A tweet from the Polish Border Guard Sunday said that "patrols of officers and soldiers reported that last night shots were heard once again on the Belarusian side near the border with Poland."
European officials too have accused Belarus of encouraging people to cross illegally into Poland, and its other EU neighbors, as part of efforts to put pressure on the bloc over sweeping sanctions it imposed on Minsk.
The sanctions by the EU, the US and Britain in June were a coordinated response to the Lukashenko government's forced landing of a Ryanair flight and arrest of an opposition journalist as well as "continuing repression" in the former Soviet state.