Riot police and officers on horseback forcibly separated crowds of Dutch and English football supporters who were gathering on the narrow streets and bridges in Amsterdam’s red light district hours ahead of a Europa League match between Ajax and Manchester United.

Police intervened late on Thursday afternoon after the two groups began chanting and making threatening gestures toward each other across a canal.

Mounted police separated the mob into narrow lines and then riot police on foot forced them to leave the area and cordoned it off.

Amsterdam police could be seen detaining several supporters for throwing small objects on another square in the city centre.

On Wednesday night they arrested 76 Ajax supporters suspected of seeking a confrontation with United fans.

Police spokesman Ad Smit said the men were rounded up under heightened security rules ordered by the city’s mayor and found to have had weapons including knives, brass knuckles, tear gas and clubs, as well as “a large amount of narcotics.”

They were held overnight and face varying fines of up to 600 euros ($A735).

Another 54 supporters of Belgian club Anderlecht, who were also thought to be seeking confrontation with United fans, were detained on Wednesday and sent home, and 12 people without connection to any particular team were arrested for “football-related incidents”.