Bombers have targeted staff at Israeli embassies in India and Georgia, according to officials, with Israel accusing Iran of masterminding the attacks.
In India's capital, Delhi, an Israeli embassy vehicle exploded in a high-security zone, injuring the wife of a diplomat.
Officials in Georgia said an explosive device was attached to the bottom of a diplomat's car in the capital Tbilisi, but was found and defused before it detonated.
Israeli leader Benjamin Netanyahu says Iran is behind both incidents. But Iranian officials have denied the claims as "sheer lies", the BBC reports.
Mr Netanyahu told a meeting of his Likud party MPs there had been "two attempts of terrorism against innocent civilians".
He blamed Iran for recent plots to attack Israeli targets in Thailand and Azerbaijan that were prevented and suggested the militant Islamist Hezbollah movement was also involved.
Israel's foreign ministry says the country has the ability to track down those who carried out the attacks.
In Tehran, an Iranian Foreign Ministry spokesperson denied any involvement, saying it was Israel that had carried out the attacks as part of its psychological warfare against Iran.
Iran's state news agency Irna also quotes the country's ambassador in India as denying involvement.
"Any terrorist attack is condemned and we strongly reject the untrue comments by an Israeli official," said Mehdi Nabizadeh in comments translated by Reuters. "These accusations are untrue and sheer lies, like previous times."
The BBC reports security at Israeli embassies has been tightened in recent months following warnings of potential attacks, after Iran accused Israel of a series of attacks on its nuclear scientists.
The embassy in India is guarded by several layers of security and is in a well-defended area of central Delhi, close to Prime Minister Manmohan Singh's official residence.
A spokesperson for Israel's Delhi embassy says the diplomat's car was close to the building on Aurangzeb Road when the explosion went off. He says they have no details as to who was behind the attack.
US, UK condemn
Britain's Foreign Secretary William Hague has condemned the attacks.
He has called on officials in New Delhi and Tbilisi to begin investigations into the incidents.
United States Secretary of State Hillary Clinton says her government condemns the attacks on Israeli targets.
She says the US is ready to assist with any investigation.