[REF WATCH] Tom Henning Ovrebo, who refereed Champions League semifinal on Wednesday in which Barcelona ousted Chelsea, needed police protection after the game and has been receiving death threats. The hate campaign against the Norwegian included a Facebook group titled “Kill Tom Henning Ovrebo.”

Ovrebo, who was abused by Chelsea players after the game, changed hotels that night on the advice of police and secretly exited England on Thursday under police escort.

Police in Olso, Ovrebo’s home city, are investigating threats on the internet, where “hunt him” and “kill him” posts included the referee’s address.

“We are watching closely what is being posted on the internet,” an Oslo police spokesman told the Evening Standard. “Anything we believe would threaten his personal safety will be taken seriously.”

“When you see players acting like that, fans are called fans because they are fanatics – they may feel it’s time to take action themselves,” said former international referee Graham Poll. “Players should show some restraint. They should show some respect.”