The drone hit and scorched a cornfield in the village of Osiny in the eastern Lublin province overnight, just over 62 miles from the Ukrainian border and around 55 miles from Belarus.
Iran and Belarus announced an agreement to enhance bilateral cooperation and to vigorously oppose Western sanctions, their presidents announced following talks on Wednesday.
Lithuania has revealed plans to dig a 30-mile-wide ribbon of defences on its borders with Russia and Belarus that will include minefields and bridges set to blow up in case Russia invades.