DUBAI: Iran will not leave any of "the criminal acts" of Israel unanswered, Iranian Foreign Ministry spokesperson Nasser Kanaani said on Monday, referring to the killing of Hizbollah's chief and an Iranian Guard deputy commander in Lebanon.

Brigadier General Abbas Nilforoushan was killed in Israeli strikes on Beirut on Friday, in which Hizbollah's leader Hassan Nasrallah also died.

Israel's intensified attacks against the Hizbollah militia in Lebanon and the Houthi militia in Yemen have prompted fears that Middle East fighting could spin out of control and draw in Iran and the United States, Israel's main ally.

"We stand strongly and we will act in a way that is regretful [for the enemy]" Kanaani told a weekly news conference, adding that Iran does not seek war but is not afraid of it.

Kanaani said that Iran is closely following up on matters with the Lebanese authorities, referring to the strikes that killed Nasrallah and Nilforoushan.

On Sunday, Iran's Foreign Minister Abbas Araqchi described the killing of Nilforoushan by Israel as a "horrible crime".

"There is no doubt that this horrible crime committed by the Zionist regime (Israel) will not go unanswered," Araqchi said in a statement addressed to the commander of the Islamic Revolutionary Guard Corps, Major General Hossein Salami.

Iran's parliament speaker Mohammad Baqer Qalibaf said that Iran-alligned armed groups would carry on confronting Israel with Tehran's help following the killing of Nasrallah, Iranian state media reported.

An alliance known as the Axis of Resistance, built up over decades with Iranian support, includes the Palestinian group Hamas, Hizbollah in Lebanon, Yemen's Houthis, and various Shi'ite Muslim armed groups in Iraq and Syria.

"We will not hesitate to go to any level in order to help the resistance," Qalibaf said.

 - Reuters