Three Hull City Fans were arrested during clashes in Belgium before and after the Hull City v Lokeren match.
Officers from Humberside say they are working with local police in Belgium looking at any offences which may have been committed by Hull fans either before or after the match last night.
Three arrests were made, two for being drunk and disorderly and one for criminal damage.
Humberside Police say they will take extra precautions to ensure a repeat does not happen at the return leg in Hull next week.
More top news
Dry, bright and sunny times ahead
A three-year-old boy has drowned at David Lloyd club on Tongue Lane in Leeds
A three-year-old boy has been taken to hospital with 'drowning-related injuries' following an incident at a pool in Leeds.