A video has emerged of AZ Alkmaar fans setting off fireworks through the night near the West Ham players hotel.
A website called www.hooligans.cz published the footage on social claiming it to be to be from the early hours of this morning.
It has become a fairly regular feature of away trips at this stage of important competitions.
However, it is veryunlikely that the West Ham will be affected by the prank as they prepare to play the second leg of the Europa Conference League semi final this evening.
Most clubs hand out ear plugs to players before a big game knowing there is a possibility of this sort of event happening, particularly in Europe where fireworks are more freely available than in the UK.
West Ham go into the European cup game 2-1 up knowing any draw or win will take them to the Europa Conference League final in Prague on 7th June