A smoke bomb which engulfed the stands during the crucial Dutch football league match between Ajax and PSV Eindhoven injured at least 15 people.
The referee was forced to stop the game between the two rival Eredivisie clubs after just five minutes after thick black smoke billowed out from the terraces at the Philips Stadion. Video footage of the smoke bombs being let off were widely shared on social media.
Ten fans, four security guards and a steward suffered respiratory or eye problems as a result of the smoke, reported Dutch news agency ANP.
A 35-year-old man has since been arrested on suspicion of setting off the device.
Referee Kevin Blom swiftly restarted the match, PSV beating Ajax 1-0 thanks to a 25th minute free-kick from Jurgen Locadia.
The defeat dealt a massive blow second-place Ajax's changes of winning a 33rd league title as they now trail leaders Feyenoord by four points with just two games to go.
Feyenoord can clinch the Eredivisie title for the first time since 1999 with a victory away at Excelsior on 7 May.