Two of Iran’s heavily armed proxy groups in the region have threatened to target US interests if Washington intervenes to support Israel in its conflict with Hamas.
The Houthi Movement in Yemen and a powerful Iraqi militia group both issued identical statements, which can be a sign that Tehran is willing to leverage its loyal proxies to flex its muscle against the United States.
The comments come amid strong support by the United States for Israel's response to the attacks and a US pledge to rapidly provide additional munitions to Israel and deploy a carrier strike group to the Eastern Mediterranean.
In Yemen, the leader of the powerful Houthi Movement warned on Tuesday that the group would respond to any US intervention in Gaza with drones, missiles and other military options.
He said the group was ready to coordinate intervention with other members of the so-called "Axis of Resistance" which encompasses Iranian-backed Shiite Muslim factions in Iraq and Lebanon's Hezbollah group, which has already entered the fray.
The remarks came after the top US general late Monday warned Iran not to get involved in the crisis in Israel and said he did not want the conflict to the broaden, as Lebanese Hezbollah fired rockets onto northern Israel.
The White House earlier on Monday said that Iran was complicit even though the United States has no intelligence or evidence that points to Iran's direct participation in attacks in Israel by Palestinian Islamist group Hamas.
Asked what his message for Iran was, General Charles Q. Brown, the chairman of the Joint Chiefs of Staff, said: "Not to get involved."
Later on Tuesday, President Joe Biden repeated the warning in an address to the nation. "So, in this moment, we must be crystal clear. We stand with Israel. Let me say again to any country, any organization, anyone thinking of taking advantage of this situation, I have one word. Don't. Don't!"
In Iraq, Hadi Al-Amiri, a powerful Iraqi politician close to Iran and a key figure in the cross-party alliance backing the Baghdad government, also threatened to target American assets, in comments made during a tribal gathering in the capital.
"If they intervene, we will intervene...If the Americans intervened openly in this conflict..., we will consider all American targets legitimate..., and we will not hesitate to target it," Al-Amiri said on Monday.
He leads the Badr Organization, a Shi’ite political group supported by Iran that comprises a large part of Iraq's Popular Mobilization Forces (PMF), the state paramilitary organization that contains many Iran-backed factions.
If the US forces intervene in the operation al-Aqsa Storm – the codename for the Hamas attack, “we will target the American bases” as well as Israeli positions, said Abu Hussein al-Hamidawi, the secretary-general of Kataib Hezbollah, a radical Iraqi Shiite paramilitary group and part of the PMF.
The PMF has voiced its "unequivocal support" for the Palestinian factions fighting Israel and the Iraqi government has said the Palestinian operations were a natural outcome of what it calls "oppressive" policies by Israel.
In past years, Iranian-backed militias in Iraq regularly targeted US forces in Iraq and the US embassy in Baghdad with rockets, though such attacks have abated under a truce in place since last year, as Iraq enjoys a period of relative calm.
The United States currently has 2,500 troops in Iraq - and an additional 900 in Syria - on a mission to advise and assist local forces in combating Islamic State, who in 2014 seized swathes of territory in both countries.