TEHRAN -- Iran's Supreme Leader Ali Khamenei on Saturday called on all Muslims to mobilize their resources and facilities and stand by the Lebanese people and Hezbollah in the fight against Israel.

He made the remarks in a message published on his website, responding to recent Israeli attacks on Lebanon that killed both Hezbollah fighters and civilians.

Khamenei stressed that all resistance forces in the West Asia region stood by and supported Hezbollah, noting that the killing of the "defenseless" people in Lebanon once again exposed Israel's "ferocity."

He added Israel could not inflict any important harm on Hezbollah's strong structure.

Khamenei pointed to Hezbollah's success in ousting Israel from Lebanon in the past, expressing hope that the group would make Israel regretful again.

Israel began extensive airstrikes across Lebanon on Monday, marking the most significant Israeli military action in the country since 2006.

The Israel Defense Forces claimed on Saturday that they killed Hezbollah leader Sayyed Hassan Nasrallah in airstrikes on the southern suburbs of Beirut on Friday. Nasrallah's death was also confirmed by Hezbollah.