The strong police forces to be deployed in Zagreb and on the premises of the Maksimir stadium will be reinforced by an additional 625 security guards and over 100 stadium bouncers, Croatian police officials told a news conference in Zagreb on Monday.
It is expected that about 4,500 England's fans will arrive and they will be placed on the southern stand.
The game scheduled for 1900 hrs Wednesday will be covered by many TV and radio crews and press reporters.
The secretary-general of the Croatian Football Federation, Zorislav Srebric, announced the arrival of two UEFA commissioners who will monitor security measures.
A total of 34,500 tickets have been offered for sale.