Thousands of Hezbollah supporters gathered in Beirut's southern suburbs to mourn Iran's supreme leader Ayatollah Ali Khamenei on Sunday, chanting "death to America, death to Israel" while crying over the killed figure.

The U.S. military on Sunday said three service members have been killed and five seriously wounded in the operation against Iran -- the first casualties of any kind announced on the U.S. side.

The death toll from an Iranian missile attack Sunday in the Israeli city of Beit Shemesh rose to at least nine people, first responders said, in the deadliest strike in the country since the war began.

The Magen David Adom emergency service said: "In the Beit Shemesh area, MDA EMTs and paramedics have pronounced the deaths of nine" people, as well as 28 others injured, with police saying it was a direct hit on a building.

U.S. President Donald Trump on Sunday said he would "be talking" to Iranian leaders but was vague on the timing and noted that much of the country's leadership was dead.

Cheers in Tehran. Retaliation and mourning by Iran. Protests in some parts of the Muslim world, celebrations in others.

At least nine people were killed during pro-Iran protests at the United States consulate in the Pakistan megacity of Karachi on Sunday, according to a hospital toll seen by AFP.

Iranian strikes and drone attacks targeted northern Iraq, where U.S. troops are deployed, as furious protests raged in Baghdad on Sunday over the killing of Iran's supreme leader Ayatollah Ali Khamenei.

France can only "be satisfied" with the killing of Iran's supreme leader Ayatollah Ali Khamenei in U.S.-Israeli strikes, said government spokeswoman Maud Bregeon on Sunday.

Hezbollah vowed Sunday to confront the United States and Israel over their strikes on the group's key backer Iran.

"We will undertake our duty of confronting the aggression," Hezbollah chief Sheikh Naim Qassem said in a statement, adding that his group would not leave "the field of honor and resistance".

Britain's defense secretary said Sunday that "Iranian indiscriminate retaliatory attacks" to U.S.-Israeli strikes included "two ballistic missiles fired in the direction of Cyprus", but which were likely not "targeted" at the Mediterranean island.