Israel is on alert for plots to kill more Israelis overseas, Prime Minister Benjamin Netanyahu said on CBS television’s “Face the Nation” program Sunday.

“We are vigilant about the possibility that [Iran and its agents] would attack elsewhere, but I can’t give specific details. … I’m not confirming any information that we have on the Olympics,” Netanyahu said.

Five Israelis and a Bulgarian bus driver were killed in Burgas, Bulgaria last week when a suicide bomber blew himself up on a bus.  The attack and questions surrounding the terrorist’s identity has fueled speculation that Israeli athletes might be targeted next.

On Sunday, British newspaper The Sunday Times reported that Mossad agents were working to thwart an Iranian attack on Israeli athletes at the games.

Defense Ministry official Amos Gilad called the report hokum, saying the Israeli spy agency did not operate in the way described by the British paper.

Netanyahu told CBS his government has “fully substantiated intelligence” that Wednesday’s attack was carried out by the Iran-backed Lebanese militant group Hezbollah.

The prime minister told “Face the Nation” that Israel “will do whatever is necessary” to protect innocent Israelis and said “there has to be a price exacted” from the terrorists and their backers.

Iran has denied responsibility for the bombing.