The Dutch league clash between Ajax and already-relegated Groningen was halted and then called off with only nine minutes on the clock, after fireworks were twice thrown onto the pitch Sunday.

In the sixth minute of the clash in Groningen, smoke bombs were thrown onto the field. Shortly afterward, a supporter ran onto the pitch with a banner calling for the ouster of the Groningen board, prompting the referee to take the two teams off the pitch.

When the teams returned, smoke bombs were thrown again, leading to the match being called off, in line with new Dutch football guidelines brought in earlier last month.

It followed crowd violence in the Dutch Cup semifinal between Feyenoord and Ajax in early April when a cigarette lighter thrown from the crowd hit Ajax midfielder Davy Klaassen and cut his head, causing a lengthy delay to the match.

The Dutch football association then decided that all matches would be stopped immediately if a player or match official was hit by an object from the crowd.

They also decided that if an object is thrown from the terraces but misses, play will be temporarily stopped with the players sent to the dressing rooms. If the same thing happens a second time, the match is to be immediately stopped.

The new guidelines have done little to halt a growing problem for the Dutch game. Three top-flight matches on Friday and Saturday were temporarily halted because of objects thrown onto the field.