US and Canadian intelligence agencies warned Thursday that Hizbullah attacks on Jewish targets around the world could be imminent. ABC News quoted intelligence officials as saying that Hizbullah had activated sleeper cells in Canada, and that top terror operatives had left Lebanon for the US, Canada and Africa. According to the officials, Hizbullah wants to avenge February's assassination of its operations head Imad Mughniyeh in Damascus, for which the Shi'ite group holds Israel accountable. Israel has repeatedly denied the allegation. There was no reliable intelligence regarding the possible targets of such an attack, the sources told ABC News, adding, however, that Hizbullah operatives had recently been seen conducting surveillance on the Israel Embassy in Ottawa and on several Toronto synagogues. "There are concerns Hizbullah might be ready to do something along those lines," ABC quoted a senior US counterterrorism official as saying. CIA and National Security Agency officials quoted by the report said British and Canadian agencies began receiving a flow of intelligence on February 17, only a few days after Mughniyeh's funeral, regarding a possible Hizbullah attack. "They want to kill as many people as they can, they want it to be a big splash," former CIA intelligence officer Bob Baer, who claimed he met with Hizbullah leaders in Beirut last month, was quoted by ABC as saying. "They cannot have an operation fail and I don't think they will. They're the A-team of terrorism." According to officials quoted by the report, up to 20 suspected Hizbullah members have been under surveillance and their activities are being coordinated with the Iranian Revolutionary Guard. "Hizbullah would not carry out an attack in the West, or wherever this attack is going to occur, without approval from Teheran," Baer was quoted as saying.