JERUSALEM -- Israel's prime minister said Sunday that his country is on alert for plots to kill more of its citizens overseas, after speculation that last week's deadly bombing of a tour bus in Bulgaria was a rehearsal for a spectacular attack on Israel's Olympics team.
Israel blames Iran and its Lebanese Hezbollah proxies for last week's bombing at an airport in the Bulgarian resort town of Burgas, just a little more than a week before the opening of the London Games. Five Israelis, a bus driver and the bomber were killed.
While Israeli officials are tight-lipped about security procedures for its athletes, they're on high alert on the 40th anniversary of a Palestinian attack at the 1972 Olympics in Munich that killed 11 Israeli athletes and coaches.
"We are vigilant about the possibility that they (Iran and its agents) would attack elsewhere, but I can't give specific details," Prime Minister Benjamin Netanyahu told CBS television's Face the Nation program on Sunday.
He pointedly kept mum when asked whether to comment on media reports that Israel feared the Bulgaria attack was a precursor to an assault on Israel's Olympic team.
"I'm not confirming any information that we have on the Olympics," he said. Concerning media reports to that effect, he added, "I can't give you any substantiation."
The heads of the Mossad and Shin Bet intelligence agencies briefed the Cabinet on attempts by Iran and Hezbollah to carry out attacks in more than 20 countries over the last two years, the Prime Minister's Office said in a statement.
Defense Minister Ehud Barak told reporters in Israel that intelligence agencies around the world were working with the British "to minimize the chances that there will be any sort of incident during the Olympics."
"(This vigilance) is first and primarily an outgrowth of things that happened in the past, things that we all remember at the Munich Olympics," Barak said Sunday. "We must remain alert."
Israeli Foreign Minister Avigdor Lieberman is traveling to Brussels on Monday to meet his British counterpart and nine other European foreign ministers to request that they beef up security at their airports and at sites in their countries where Israelis and Jews frequent, according to a statement from Lieberman's office.
Defense Ministry policy planner Amos Gilad dismissed a report in The Sunday Times in the United Kingdom that Israel rushed spies to European capitals after the Bulgaria attack to look for an Iranian terror squad dispatched to kill Israeli athletes.
"Intelligence doesn't work that way. You don't send dozens of agents to look for ghosts," Gilad told Army Radio.
A British security official said the threat level to Israeli athletes and officials had been high even before the Bulgaria attack. He said security arrangements were assessed again following the attack, but he would not say whether they had been changed. He spoke on condition of anonymity because he was not authorized to speak to reporters.
Although penetrating formidable Olympic security would be no small challenge, Israeli counter-terrorism expert Boaz Ganor said the event remained one of the most attractive targets for terrorists because of its high profile. Potential Israeli targets include not just athletes, but Israeli tourists and fans as well, Ganor said.
"There are more groups that want to harm Israeli targets than others," he said.
Tens of thousands of police officers and security staff will be on hand to guard the games, including thousands of troops on standby. A no-fly zone also will be established over Olympic venues from July 14 to Aug. 15.
Protecting Israeli athletes at the Olympics has been a particular concern since Palestinian gunmen took 11 Israeli athletes and coaches hostage at the Munich games. They were later killed. The Israeli team will be kept away from the others in a secluded, heavily secured area, a senior Israeli intelligence official told The Associated Press.
Efraim Zinger, director of the Israeli Olympic Committee, told The Associated Press in London that "unfortunately we are part of a very distinguished list of countries" whose teams are susceptible to attack.
"Our people work and continue to work very closely with local authorities," he said. "We have the confidence the local authorities will do their utmost to protect all the Olympic athletes."