Iranian state television claimed that Wednesday missile strikes on bases in Iraq killed 80 Americans, in a report citing what it called an informed Revolutionary Guards source.

Iran launched 22 missiles overnight at the Iraqi bases used by US and other US-led coalition troops, the Iraqi army said.

"At least 80 American military (personnel) were killed in this attack," the state television website reported.

In addition, it said, unmanned aerial vehicles, helicopters and other military equipment had been severely damaged in the attack.

The Revolutionary Guards source said at least 140 targets of the US and their allies had been identified in the region and would be attacked "if the Americans commit any kind of mistake again".

The source said 15 missiles hit Ain Al-Assad base and none was intercepted by "radars of America's terrorist army".

It was the first action of Iran's promised revenge for the US killing of top Iranian general Qasem Soleimani in Iraq last week.

Iran's foreign minister appeared to suggest that the missile strikes were over for now.

But the supreme leader, who has the final say in all matters of state, said it was a "slap in the face" for the United States and revenge was yet to come.

There was no immediate confirmation of the casualties. The Pentagon said the facilities had been on "high alert" after days of steadily mounting tension and exchanges of threats of war.

The Iraqi military said it sustained no casualties. 

Iraq's prime minister's office said it had received "an official verbal message" from Iran informing it that a missile attack on US forces stationed on Iraqi soil was imminent.

"We received an official verbal message from the Islamic Republic of Iran that the Iranian response to the assassination of Qasem Soleimani had begun or would begin shortly, and that the strike would be limited to where the US military was located in Iraq without specifying the locations," the office said. 

US President Donald Trump in a tweet said an assessment of damage was being made but all was well.

“Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties & damages taking place now. So far, so good!” the president tweeted.

Mr Trump is due to deliver a televised address later on Wednesday. 

Netanyahu warns of 'resounding blow' if Iran attacks Israel
   
Prime Minister Benjamin Netanyahu warned Wednesday that Israel would strike a "resounding blow" if attacked by Iran.

"Anyone who attacks us will receive a resounding blow," the premier told a Jerusalem conference after Iran launched a salvo of retaliatory missile strikes on bases used by US troops in Iraq.

Netanyahu has described the target of last week's US drone strike -- Major General Qasem Soleimani, commander of the Iranian Revolutionary Guards foreign operations arm -- as a "terrorist-in-chief".

"Qasem Soleimani was responsible for the deaths of countless innocent people, he destabilised many countries for decades, he sowed fear and misery and anguish and he was planning much worse," Netanyahu said.

"He was the architect and driver of Iran's campaign of terror throughout the Middle East and the world."

The Israeli premier praised US President Donald Trump for "acting swiftly, boldly, and resolutely" in killing Soleimani in the Iraqi capital Baghdad. 

A senior Iranian official on Monday warned the Israeli cities of Haifa and Tel Aviv would be turned "to dust" if Washington carried out further military action in response to its retaliatory moves.