Senior Iraqi and Yemeni leaders aligned with Iran and in charge of heavily armed groups have threatened to target U.S. interests if Washington intervenes to support Israel in its conflict with Hamas in Gaza.

The comments come amid strong support by the United States for Israel’s response to the attacks and a U.S. 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 U.S. 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 Shi’ite Muslim factions in Iraq and Lebanon’s Hezbollah group, which has already entered the fray.

Yemen’s Houthi movement has battled a Saudi-led coalition since 2015 in a conflict that has killed hundreds of thousands, during which it has targeted strategic assets in the Gulf, most notably energy facilities in Saudi Arabia.

Yemen has enjoyed a year of relative calm as peace negotiations gain traction.

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 would 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 Organisation, a Shi’ite political group supported by Iran that comprises a large part of Iraq’s Popular Mobilisation Forces (PMF), the state paramilitary organization that contains many Iran-backed factions.

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 U.S. forces in Iraq and the U.S. 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.