Millwall striker Neil Harris admits he feared for his safety when West Ham fans invaded the pitch during this week's Carling Cup clash.
Harris said: "It was extremely hostile and volatile. My concern was for my team-mates.
"At one stage it wasn't very pleasant.
"We've had it at Millwall when fans come on to celebrate and everyone makes a big hoo-ha about it.
"Anything can happen when they are on the pitch but most of the time fans are on the pitch to celebrate a goal, not to attack players.
"I've played in big local derbies and red-hot atmospheres. They are terrific games to play in.
"It means so much to the supporters but sometimes they get a little bit over-zealous."