A group of about 50 migrants broke through defenses on the border with Belarus and entered Poland near the village of Starzyna, Polish police said on Sunday.

"Yesterday, before 5 p.m., around 50 people broke into Poland near Starzyna," Podlaska police said on Twitter, adding that 22 Iraqi citizens were subsequently arrested.

The police also said they were under attack after 8:00 p.m. in the vicinity of Klukowicze-Kolonia as migrants tried to forcibly cross the border. One officer's head was hit by a stone and a police car was damaged. 

(With input from Reuters)