Iraqi Prime Minister Mustafa al-Kadhimi escaped unharmed in an assassination attempt by armed drone in Baghdad on Sunday, officials said, in an incident that dramatically raises tension in the country weeks after a general election disputed by Iran-backed militia groups.

Six members of Kadhimi’s personal protection force stationed outside his residence in the Green Zone were wounded, security sources told Reuters.

Three drones were used in the attack, including two that were intercepted and downed by security forces while a third drone hit the residence, state news agency INA quoted a spokesman for the interior ministry as saying.

A spokesman for the armed forces commander in chief said the security situation was stable inside the fortified Green Zone, which houses the residence, government buildings and foreign embassies, after the drone attack.

No group immediately claimed responsibility for the attack.

It came two days after violent clashes in Baghdad between government forces and supporters of Iran-backed political parties, most of which have armed wings, since those groups lost dozens of seats in parliament after a general election on October 10.

Kadhimi has ordered an investigation into the deaths and injuries of demonstrators and security forces in those clashes.

President Barham Salih condemned the attack as a heinous crime against Iraq. “We cannot accept that Iraq will be dragged into chaos and a coup against its constitutional system,” he said in a tweet.

Shia Muslim cleric Moqtada al-Sadr, whose party was the biggest winner in last month’s election, called the attack a terrorist act against Iraq’s stability that aimed to “return Iraq to a state of chaos to be controlled by non-state forces”.

The US State Department condemned the attack and offered assistance with the investigation.

“This apparent act of terrorism, which we strongly condemn, was directed at the heart of the Iraqi state,” spokesman Ned Price said in a statement.

Saudi Arabia’s foreign ministry said the attack was a “cowardly terrorist act”, Saudi-owned Al-Arabiya TV reported.

Images published by INA showed damage to some parts of the Prime Minister’s residence and a damaged SUV vehicle parked in the garage.

Remains of a small explosive-laden drone used in the attack were retrieved by security forces to be investigated, a security official with knowledge of the attack told Reuters.

“It’s premature now to say who carried out the attack,” the security official on condition of anonymity as he was not authorised to comment on security details.

“We’re checking our intelligence reports and waiting for initial investigation results to point the finger at perpetrators.”

The Iraqi military said in a statement the attack targeted Kadhimi’s residence and that he was in “good health”. It provided no further detail. Kadhimi’s official Twitter account said the Prime Minister was safe, and called for calm. ReutersTwo government officials said Kadhimi’s residence had been hit by at least one explosion.

Western diplomats based nearby in the Green Zone said they heard explosions and gunfire in the area.

The groups leading protests and complaints about the result of the October 10 vote are heavily armed Iran-backed militias that lost much of their parliamentary power in the election. They have alleged voting and vote-counting irregularities, allegations rejected by the country's election officials.

Demonstrations by their supporters turned violent on Friday when protesters pelted police with stones near the Green Zone, injuring several officers.

The police responded with tear gas and live gunfire, killing at least one demonstrator, according to security and hospital sources in Baghdad.

Independent analysts say the election results were a reflection of anger towards the Iran-backed armed groups, which are widely accused of involvement in the killing of nearly 600 protesters who took the street in separate, anti-government demonstrations in 2019.