Press TV - The United States has threatened Iran with a response over the unrest in the Iraqi city of Basra, saying Tehran will be held accountable for any possible harm to the American citizens stationed there.

The White House issued the warning on Tuesday, days after protests over alleged corruption and government neglect escalated into deadly violence in the oil-rich port city.

At least 12 protesters were killed in Basra and many of its institutions and buildings.

Meanwhile,�three mortar shells struck the ultra-secure green zone in Baghdad, which houses Iraqi authorities and the US Embassy, on Friday and�unknown assailants fired Katyusha rockets at the airport in Basra, which also houses the US consulate, on Saturday.

White House Press Secretary Sarah Huckabee Sanders blamed Iran. �Over the past few days, we have seen life-threatening attacks in Iraq, including on the United States consulate in Basra and against the American embassy compound in Baghdad.�

�Iran did not act to stop these attacks by its proxies in Iraq, which it has supported with funding, training, and weapons,� she added.

�The United States will hold the regime in Tehran accountable for any attack that results in injury to our personnel or damage to United States government facilities. America will respond swiftly and decisively in defense of American lives.�

The White House's statement�is in sharp contrast with the assertion of Iraqi officials, who�have blamed the US, Daesh terrorists and remnants of former Ba�ath regime for the recent wave of violence.

Angry demonstrators on Friday stormed�Iran's fortified consulate, setting the building ablaze and causing serious financial damage.

"We have complete information and documents that show the US embassy and consulate in the country caused the Basra unrest," Abu Mahdi al-Muhandis, the second-in-command of Hashd al-Sha�abi, a volunteer anti-terror group, said on Sunday.

Muhandis�said it was actually meant to sow discord among different Iraqi political parties and movements.

Iraqi Prime Minister�Haider al-Abadi, who visited Basra on Monday, condemned the Friday attack on the Iranian�consulate.

In recent months, US President Donald Trump has repeatedly touted his administration�s success in defeating Daesh and destroying its so-called caliphate in Iraq and neighboring Syria.

However, the Pentagon acknowledged last month that the terrorist organization appeared�to be �well-positioned to rebuild and work on enabling its physical caliphate to re-emerge.�

The US first deployed forces to Iraq in 2003 under the banner of "war on terror" two years after invading Afghanistan under the same pretext. The deployment was followed by rampant violence and chaos, which set the stage for the rise of Daesh in 2014.