PHOTOS: Hundreds storm US embassy in Baghdad

Hundreds of protesters stormed the United States embassy in Baghdad on Tuesday in a demonstration against the American airstrikes that had killed two dozen members of an Iran-backed militia group in Iraq and Syria over the weekend.

The demonstration witnessed an attempt by the protesters to break into the heavily-guarded embassy premises.

Security personnel fired tear gas to repel the attack.

Video and photos on social media showed demonstrators smashing the windows of the embassy and burning items outside its walls, The New York Times reported.

Protesters attacked what they deemed to be US' disproportionate response -- the killing of 24 militiamen on Sunday in retaliation for the death of an American contractor on Friday.

The US carried out five airstrikes in Iraq and Syria on facilities controlled by Iran-backed Kataib Hezbollah.

At least 25 people were killed and 51 wounded in the strikes.

US officials told CNN that the strikes were carried out with F-15 Strike Eagle fighter planes and targeted weapons storage facilities, and command and control locations used by Kataib Hezbollah in response to the killing of the US civilian contractor in a rocket attack on an Iraqi military base.

'Iran killed an American contractor, wounding many. We strongly responded and always will. Now Iran is orchestrating an attack on the US Embassy in Iraq. They will be held fully responsible. In addition, we expect Iraq to use its forces to protect the Embassy, and so notified!' US President Donald Trump wrote on Twitter.

The Pentagon said the locations had been used 'to plan and execute attacks' on joint US-Iraq forces bases near Kirkuk.

The airstrikes and protests have created new tensions between allies Washington and Baghdad, with Iraqi police and soldiers among the killed and wounded.

They come at a time of unrest as mass protests across Iraq challenge the nation's precarious government.

By the end of the day, there were calls to end the 'American occupation' and demands for the US military to leave Iraq.

Baghdad warned on Monday that its relations with the US were at risk following the strikes.

The strikes and protests also come at a time of high tensions between the US and Iran, and have stoked fears of a new proxy war in the Middle East.

Washington, DC has tightened the economic squeeze on Tehran this year through its 'maximum pressure' campaign, while Iran has responded with what it calls for 'maximum resistance', including reducing its compliance to the international nuclear deal.