The death toll in the Israeli strike on the Iranian consulate in Damascus rose to 16, said the Syrian Observatory for Human Rights on Wednesday.
Director of the rights monitor told AFP that dead include eight Iranians, five Syrians and one member of the Lebanese Hezbollah group, as well as two civilians.
Iranian leaders on Wednesday renewed their promise to hit back after the strike that destroyed Iran's consulate in Syria.
Two elite Iranian generals were also killed.
Iran’s President Ebrahim Raisi said Wednesday the attack “will not remain without answer.”
The US is concerned the deadly strike could trigger new attacks on American troops by Iranian-backed militias in Iraq and Syria, said Lt. Gen. Alexus Grynkewich, the top US Air Force commander for the Middle East.
Iran and its allies — including Hezbollah and other armed groups in Syria, Iraq and Yemen — have repeatedly traded fire with Israel and the US since the start of Israel's war in Gaza.
By attacking an Iranian diplomatic station, Israel's apparent escalation has raised fears that the devastating six-month war against Hamas could spill over into the entire Mideast region and beyond.
Israel faces growing isolation as international criticism mounts over its killing of six foreign aid workers this week who were helping deliver desperately needed food in Gaza. The United Nations says much of the population in northern Gaza is on the brink of starvation.
Israel's war in Gaza has killed nearly 33,000 Palestinians, mostly women and children, the territory's Health Ministry says. The war began on Oct. 7, when Hamas-led gunmen stormed into southern Israel, killing some 1,200 people, mostly civilians, and taking around 250 people hostage.