The news that Chelsea manager Avraham Grant received anti-Semitic death threats in the mail has been met with shock amongst his friends and the Jewish community in England. However, communal leaders are cautioning that at this point in time it should only be taken as an isolated incident and not as symptomatic of a wider rise in anti-Semitism in British soccer. Police in the English county of Surrey confirmed on Wednesday that a package containing a "mysterious powder" had been sent to the Chelsea FC training ground in Cobham on Tuesday. A note inside the package alleged that the substance was lethal and was accompanied by an anti-Semitic letter. However, after the training ground was initially sealed off, Surrey Police confirmed that the powder was in fact harmless. The letter called Grant a "back-stabbing Jewish bastardâ€š" and promised him a "slow and painful death" while also threatening sexual assault against his wife, Tzofit. Grant and the Chelsea first team were not present at the Chelsea training ground at the time, having flown to Athens to play Olympiakos in the Champions League knockout stages, a match which ended 0-0. Surrey police say that the investigation is ongoing. "I was surprised to hear about it, because in the last few years we have hardly heard about anti-Semitism [in soccer], then suddenly [Grant] received this letter," former Liverpool player and long-time friend of Grantâ€š Avi Cohen, told The Jerusalem Post. Cohen spoke of how anti-Semitism had virtually disappeared from the game since his own playing days in the 1980s. "It was hard in the '80s because of the political situation [in England]. Sometimes I could hear shouts from the crowd, such as "yid" but it was nothing too serious. Now you don't hear from any of the players who play abroad about this problem. Not from Turkey, Belgium or Spain," he said. Cohen added that he felt this was an isolated incident, saying that Grant had never spoken to him of suffering anti-Semitic abuse from crowds in the past. A spokesman for the CST, an organization which aims to protect the Jewish community in Britain, said: "There was a spate of disturbing white powder incidents in 2001, but for now this appears to be an isolated case against a high profile individual. "We are, however, concerned at the generally high levels of anti-Semitic incidents that are faced by the Jewish community." A CSTspokesman added: "In a football context, this is often concentrated around Tottenham Hotspur, and also in lower level football against actual Jewish teams. We have discussed these issues with the Football Association and Police, and have their support in challenging it." When Grant first took on the job of Chelsea coach, sections of the Stamford Bridge support, who felt that he had helped push out the former manager Jose Mourinho, were accused of being anti Semitic. At the time Chelsea Chairman Bruce Buck told the Agence France Presse: "We welcome all constructive points of view. But there have been a few which could be viewed as racist and anti-Semitic and that must stop immediately. "This is one thing we will not tolerate, whether in written correspondence, on the chat pages, on posters or banners, or through singing and chanting." However, Chelsea has denied that fans of the club were to blame for the death threat Grant received on Tuesday. "There is absolutely no evidence that Chelsea fans were in any way connected to this incident," a Chelsea source told the Post. "I think we have taken great steps to stamp out all forms of discrimination at Stamford Bridge," the source added. Israeli sports Web site one.co.il reported on Wednesday that Grant issued a statement reassuring his fans that he is ok, although this has not been confirmed officially. Meanwhile, in response to his team's drab 0-0 draw with Olympiakos, Grant was disappointed but looked forward to the return tie in two week's time. "This was a game that we played less well than previous games," he said. "We only created a couple of chances so it's a little disappointing. The performance could have been better but the result was good." Grant drew criticism for his decision to rest key players Frank Lampard and John Terry with one eye on Sunday's League Cup final against Tottenham. "In football, I never gamble and we put a strong team out," was Grantâ€š response. "Anything I do is questioned, I'm ok with this. They are not easy decisions but it is my job."