A 17-year-old has handed himself into police after a seven-year-old boy was struck in the face by a flare at a football match.
South Yorkshire Police said a flare was thrown in the crowd shortly before half-time on Saturday as Barnsley played Hull City at Oakwell stadium.
Officers said it is believed to have been thrown by a Hull City fan and hit the child, who was a fan of the same club, in the face. He suffered minor injuries.
Humberside Police, who are also investigating, said the boy received treatment at the scene and returned to watch the rest of the match.
The teenager presented himself at Clough Road Police Station in Hull and was questioned by officers on Saturday.
Chief Inspector Blake Neale said: "Behaviour of this nature will not be tolerated as families should feel safe to be able to go to watch their teams play without the fear of this type of incident.
"Police officers work closely with the ground's stewards and tonight one supporter had been arrested on entry to the ground when he was found in possession of a flare.
"We are working closely with our colleagues in South Yorkshire Police, Hull City and Barnsley football clubs to conduct a thorough investigation, and whoever is found to be responsible will be dealt with robustly."
A spokesperson for Barnsley said: "Barnsley FC do not tolerate such actions from any individual(s) and will continue to assist South Yorkshire Police with their investigation.
"Having been tended to by stewards and our medical team, the club were pleased that the young supporter felt comfortable enough to return to his seat to watch the remainder of the fixture."
Hull City have been contacted for comment.
The boy's ordeal wasn't the only dangerous incident to have taken place at a football match on the weekend of fireworks night.
Non-league club Hashtag United posted footage of a firework exploding on a pitch in Essex and striking one of the players on Friday.
Footballer Matas Skrna narrowly avoided serious injury after the firework landed near him on the turf, with the sparks from the explosion striking his legs.
Another football match was disrupted by fireworks on Friday when Waterford's game against Shamrock Rovers in the Irish Premier League was temporarily halted.
Television footage of the match showed several fireworks exploding above the pitch and showering the players.