(AP) — Large groups of fans invaded the field and threw flares before being chased away by police in a German second-division soccer game between Dynamo Dresden and Hertha Berlin on Saturday.

Dresden fans in the club’s yellow and black colors ran the length of the field toward a section containing fans of visiting team Hertha, who also jumped a fence and moved toward the field. Lit flares were thrown from both sides, some of them landing near spectators, and some fans seemed to trade blows.

Police then stormed onto the field from an entrance in the corner of the stadium and chased dozens of Dresden supporters back toward the other end.

It was not immediately clear if anyone was injured or if there had been arrests.

Referee Sven Jablonski stopped the game and took the players off for over 15 minutes. During that time, police formed two lines across the field facing the Dresden supporters. A banner in Hertha’s blue and white colors was set alight and displayed in the Dresden end.

The game eventually resumed. It was the second stoppage after an earlier delay when fans let off pyrotechnics and smoke filled the stadium. Hertha won the game 1-0.

Also, there was fan unrest at the final whistle when Borussia Dortmund beat Stuttgart 2-0 in a top-division game. A group of Stuttgart fans approached the field but stopped behind advertising boards and a chair was thrown onto the field.