Police are investigating after Burnley's 3-0 home win against rivals Blackburn was temporarily halted by fireworks landing on the pitch.
Several fireworks, which appeared to have been let off from outside Turf Moor during the closing stages, landed close to the players and forced referee David Coote to briefly pause play.
After Burnley's win lifted them back to the top of the Championship, police praised the majority of fans at the east Lancashire derby for their good behaviour.
Officers made five arrests, while a "small number of fans were ejected from the stadium".
A police statement read: "We are also aware of isolated pockets of disorder and missile throwing during the game which will form part of the post-match investigation.