The death of seven Israelis in a bombing in Bulgaria on Thursday has notched up Middle East tensions, with Israeli Prime Minister Benjamin Netanyahu accusing Iran for the attack and vowing to retaliate with force.

“This is an Iranian terror attack that is spreading throughout the entire world. Israel will react powerfully against Iranian terror,” he said.

Netanyahu did not offer any evidence, but international experts do not rule out Iranian involvement, given the assassinations in Iran of civilian scientists that were attributed to Israeli agents.

Israeli officials have declared that they will hold Lebanon’s Iran-backed Hizbollah responsible for any attack on Israelis overseas, which will be treated as if it targeted Israelis in Israeli territory.

For all the world knows, the bombing was linked to something that has nothing to do with Israeli-Iranian tensions over Tehran’s nuclear programme or the killings of Iranian nuclear scientists, but Israeli leaders are not going to accept that.

The attack came on the eve of the 18th anniversary of the bombing of a Jewish community centre in Argentina that was also blamed on Iran.

Israeli media are speculating that Thursday’s attack in the Bulgarian tourist hub of Burgas was engineered by Hizbollah in conjunction with the Al Quds force of Iran’s Revolutionary guards. They suggest that Hizbollah used local agents for the bombing and point out that some 12 per cent of the Bulgarian population are Muslims.

Israel accused Iranian agents of targeting Israelis for attacks in Thailand and Kenya, Georgia, India and Azerbaijan last year to avenge the killings of Iranian scientists attributed to Israel’s super-secret Mossad network.

According to Trita Parsi, president of the National Iranian American Council, US officials have privately expressed “concern that one of the purposes of Israeli attacks in Iran has been to generate an Iranian response that could serve as a casus belli for Israel. That way, Israel could target Iran’s nuclear facilities without paying the heavy political cost of starting a preventive war.”

In January this year, it was reported that Bulgarian security forces thwarted a similar attack against a bus full of Israeli tourists in what was then described as a Hizbollah attempt to exact revenge for the 2008 killing of one of its top operatives, Imad Mughniyeh, in a car-bomb explosion in Damascus.

The question now is when and in what form Israel will retaliate for the Burgas bombing. It is politically important for the Israeli establishment to hit back when Israelis die in attacks attributed to the country’s “enemies.”

However, any Israeli retaliation against Iran has to be seen in view of the uncertain and sensitive situation in the region. The raging conflict in Syria and tensions over the dispute over the Iranian nuclear programme could prompt Tehran and Hizbollah to act in an unpredictable manner. For the moment, speculation is that Israel will carefully consider whether to retaliate now, or wait for an opportune time and then settle the score, if there is one indeed.