Thousands of Sudanese police are on alert ahead tomorrow morning's World Cup football qualifier play-off between Egypt and Algeria in Khartoum.
Sudanese officials say 15 thousand police will be deployed to prevent a repeat of the weekend's violence in Cairo, where Egypt's win left the group deadlocked.
There will be strict segregation of fans inside the stadium.
The capacity has been cut by 6,000 - to 35,000 - and supporters of each side will get 9,000 seats each.
At least 32 people were injured following the weekend's game, and the next day Egyptian businesses in Algiers were ransacked.
Before the Cairo game, three Algerian players were injured when their team bus was pelted with stones.
Thousands of fans from both countries have already arrived in Khartoum for the play-off, arranged at a neutral venue by football's governing body Fifa after the teams could not be separated at the top of their group.
Sudanese officials say they are expecting 48 flights from Algeria and 18 from Egypt. A further 2,000 Egyptian fans are expected to travel by road.
Hotels in Khartoum are already booked out ahead of the game, and the authorities have set up two camp sites for rival fans several kms apart.
The stakes for each country are high. The last time either team was in the World Cup finals was 1990 for Egypt, and 1986 for Algeria.
There is a history of trouble between supporters of the two teams. Riots broke out in Egypt in 1989 after an Egyptian win in Cairo.