A US air strike in the Iraqi capital on Wednesday killed a senior commander from a pro-Iran armed group who was involved in attacks on American troops in the region, the US military said.
Washington launched a wave of strikes on Iran-linked targets in Iraq and Syria last week following the killing of three American troops in neighbouring Jordan on January 28, and the US Central Command (CENTCOM) said the commander killed Wednesday was targeted "in response to the attacks on US service members".
The strike killed "a Kataeb Hezbollah commander responsible for directly planning and participating in attacks on US forces in the region," according to CENTCOM, which said there are "no indications of collateral damage or civilian casualties at this time".
"The United States will continue to take necessary action to protect our people. We will not hesitate to hold responsible all those who threaten our forces' safety," it added.
Kataeb Hezbollah — which announced it was suspending attacks against US forces after the deadly Jordan attack — confirmed a commander who was responsible for the "military file" in Syria had been killed, identifying him as Abu Baqr al-Saadi.
The Hashed al-Shaabi, a coalition of mainly pro-Iran paramilitaries — of which Kataeb Hezbollah is part — now integrated into Iraq's regular security forces, also confirmed Saadi's death in a statement.
An interior ministry official said a total of three people —two Kataeb Hezbollah leaders and their driver — died in the strike, which was carried out by a drone in the east Baghdad neighbourhood of Mashtal.
An AFP photographer said security forces were deployed in the neighbourhood, barring access to it after the attack.
Later in the evening, the remains of a car were removed from the area.
Iraqi authorities on Thursday slammed the strike as a "blatant assassination" in a residential neighbourhood of Baghdad.
"This path pushes the Iraqi government more than ever before to end the coalition's mission which has become a factor of instability for Iraq," said Yehia Rasool, the military spokesman for the Iraqi prime minister.
Iraq's pro-Iran Al-Nujaba movement in a statement promised a "targeted retaliation", assuring that "these crimes will not go unpunished".
The group added that American "violations" will not cease without "a firm official position from the Iraqi government".
Palestinian group Hamas also condemned a "violation of Iraq's sovereignty and security", according to a statement.
US and allied troops have been attacked more than 165 times in the Middle East since mid-October in a campaign waged by Iran-backed armed groups angered by US support for Israel in the war in Gaza.
Lebanon's Hezbollah said "resistance movements in the region have total confidence" in their Iraqi counterparts and the commander's killing will only encourage them to continue acts they say are in support of Palestinians.
The United States considers Kataeb Hezbollah a terrorist group.
The Hashed al-Shaabi has said that 16 of its fighters were killed and 36 people wounded in US strikes on Friday, which Washington said hit 85 targets at seven different sites in Iraq and Syria.
"Targeting the Hashed al-Shaabi is playing with fire," the group's leader Faleh al-Fayyad warned on Sunday.
The Syrian Observatory for Human Rights war monitor said at least 29 pro-Iran fighters were killed in Syria.
The United States and Iraq opened talks on the future of the US-led troop presence in January, following a request by the Iraqi prime minister for a timetable for their withdrawal.
Washington has some 900 troops in Syria and 2,500 in Iraq as part of an international coalition against the Islamic State group.
Its troops in Iraq are deployed at the invitation of Baghdad, but those in Syria are located in areas outside Syrian government control.