Police are monitoring the home of Norwegian referee Tom Henning Ovrebo after his decisions in Wednesday's Champions League semi-final clash between Chelsea and Barcelona triggered an outpouring of anger on the internet.

Chelsea issued a statement on Thursday condemning reported threats made against Ovrebo, who British media said had to be "smuggled out" of the country under police escort and advised to change hotels following last night's events.

Chelsea fans were furious Ovrebo did not award them a penalty despite several strong appeals during the 1-1 draw in London which sent Barcelona into the final on away goals.

Coach Guus Hiddink described Ovrebo's refereeing as the worst he had ever seen and British media reported that internet threats had been made against the Norwegian official.

Oslo police said there were no threats against Ovrebo in Norway but decided to place police patrol at his residence to keep the calm during a period of "intense media interest".

"This is not a police matter for the time being," Oslo police spokesman Joern Jorgensen said.

"Because of media interest at the (Oslo) airport, he was escorted home by police. There is also a patrol at his home," Jorgensen said. "There have been no threats, but if anything happens we are ready."

Ovrebo, who has officiated in Champions League matches since 2001 and taken charge of internationals, overnight became an Internet hate object for Chelsea supporters.

On social network website Facebook, a number of clubs were created by "Haters of Tom Henning Ovrebo" calling on him to hang up his boots or be demoted to work in Norway's amateur seventh division ladies club level.

"Because of all the circumstances after the game UEFA has asked us not to speak to the press for the moment," Ovrebo told Norwegian news agency NTB via text message.

REMONSTRATED FURIOUSLY

Several Chelsea players, notably striker Didier Drogba, remonstrated furiously with the referee after the heart-breaking tie, which was settled by Andres Iniesta's stoppage-time goal.

"Following media reports claiming threats have been made against the referee of last night's game, Chelsea Football Club would like to make clear that it condemns any form of threat against players, officials or supporters," the club said.

"Everybody connected with Chelsea is very disappointed with the events of last night. However, we would stress that we have received no evidence that Chelsea fans are involved in any of the alleged threats reported," the club said, adding that the British police had not received any complaints.

Chelsea's Hiddink pointed to two questionable handball decisions, a shirt-tug on Drogba and, most blatant of all, when Florent Malouda was pulled down by Barcelona's Daniel Alves inside the penalty area in the first half. The referee gave Chelsea a free kick outside the box.

Rune Pedersen, head of Norwegian soccer referees, said Ovrebo was "doing well under the circumstances."

"He has received phone calls and texts, so we believe he has a certain understanding on the magnitude," Pedersen told Norwegian website VG Nett after speaking to Ovrebo in Oslo.

"Tom Henning is a very strong person. He is certainly not happy about all the fuss, but to me it seems like he's doing all right -- and he understands that many want to discuss what has happened but he also feels confident on most of the situations."

Police had to deal with a similar situation in 2004 when the Swiss referee Urs Meier was given protection after his personal details were published by British media.

Meier had angered England fans and media after disallowing a goal in the last minute of the Euro 2004 quarter-final between England and Portugal which would have given England a 2-1 win and a place in the semi-finals. The match went to a penalty shootout and England lost.