Amsterdam authorities are beefing up security for Thursday night's first-leg Europa League match between Ajax and Manchester United, saying there was "an increased chance of confrontation" between fans.
"There is a increased chance of confrontation between supporters groups and possibly possession of weapons," Amsterdam's city council said in a statement.
"Therefore Mayor Eberhard van der Laan has proclaimed a safety-risk area ahead, during and after the game at the Ajax ArenA," which will allow police to deploy extra members and search for weapons.
Some 2,500 Red Devil supporters have bought tickets, the statement said, but it was expected another group of between 1,000 and 2,500 fans will buy tickets at the stadium.
"Information is that there'll be a 100 hardcore Manchester United supporters among them," the statement said.
Police will control the area around the ArenA -- where in past years ugly scenes between Ajax fans and those from visiting clubs have broken out -- from 4.00 pm (1500 GMT) on Wednesday to 12.00 am (2300 GMT), the statement said.
But recent clashes at Ajax were not only confined outside the stadium.
In December an Ajax fan tried to attack AZ Alkmaar goalkeeper Esteban Alvarado, prompting the team to leave the pitch in protest against lack of security. He received a four-month jail sentence.
The clash between the two clubs in the Europa League following third placings in their respective Champion's League groups is seen as one the highlights of the rounds-of-32.