"The tragedy today ... should be an alarm for all of us that we need to deal with and unless we deal with it seriously, it will engulf all of us," Mohammad Javad Zarif said in Rome after talks with his Italian counterpart, Emma Bonino, on Tuesday.

Earlier the day, the spokesperson for Iran's Foreign Ministry accused Israel of being behind the attack outside Tehran’s Embassy in Lebanon.

“[The bombings are] an inhumane crime and spiteful act done by Zionists [Israelis] and their mercenaries," Marzieh Afkham told IRNA news agency.

The Tuesday attack, carried out by two suicide bombers in the predominantly Shia neighborhood of Bir Hasan, killed at least 25 people including an Iranian diplomat and injured over 150 others, security sources told The Daily Star. 

The Syrian government, one of Iran’s main allies in the region, also deplored the attack.

"The Syrian government firmly condemns the terrorist attacks carried out near the Iranian embassy in Beirut," according to Syria’s state television.

“The odor of petrodollars is rising from the attacks in Syria, Lebanon and Iraq,” the TV added. Syria accuses Persian Gulf states including oil-rich Saudi Arabia of funding and arming rebels seeking the overthrow of Syrian government.

Speaking to Hezbollah’s al-Manar television, Syria's Information Minister Omran al-Zoubi also accused Saudi and Israeli intelligence of being behind the attack.

United Nations Secretary-General Ban Ki-moon condemned the attack, extending his condolences to the governments of Iran and Lebanon and calling for "expeditious" justice.

US Secretary of State John Kerry condemned the attack against Iranian assets, calling the bombing "senseless and despicable terrorism."

NTJ/BA