Anders Frisk

London: Chairman of Uefa?s referees? committee, Volker Roth hinted on Monday that referees could strike after Anders Frisk was forced to retire due to death threats.

?We cannot just do nothing,? said Roth. ?There will be a demonstration of solidarity among the referees as you have never seen before.

?I am really not in favour of strikes but we must consider measures,? he told a German newspaper.

Frisk is one of Europe?s top referees and had been earmarked for the 2006 World Cup in Germany. He announced on Friday he was retiring, saying ?these last few weeks have been the worst of my life?.

The 42-year-old was in charge of Barcelona?s 2-1 first leg victory over Chelsea in the Champions League last month.

Chelsea coach Jose Mourinho said his Barcelona counterpart Frank Rijkaard had talked with Frisk in the dressing room at halftime in Spain.

Chelsea striker Didier Drogba was sent off by Frisk early in the second half. There were scuffles in the tunnel after the game and Chelsea refused to attend post-match press conference.

Chelsea won the second leg 4-2 to reach the quarter finals.