Two US troops killed in rocket attack on base near Baghdad

Al Arabiya reported Wednesday night that sites belonging to the Popular Mobilization Forces were being shelled in eastern Syria, near the border with Iraq.

US Army soldiers keep watch on the US embassy compound in Baghdad, Iraq January 1, 2020 (photo credit: DOD/LT. COL. ADRIAN WEALE/HANDOUT VIA REUTERS)
US Army soldiers keep watch on the US embassy compound in Baghdad, Iraq January 1, 2020
Two US troops and a British national were killed in a rocket attack on Iraq's Taji military camp north of Baghdad on Wednesday. Unidentified aircraft carried out airstrikes against Iranian-backed militias in eastern Syria soon after the attack, killing at least 18 Iraqi nationals.
A US official told AFP that one US soldier, one US contractor and one British soldier were killed in the attack. Arab reports indicated that about 12 other soldiers were injured in the attack as well. One Polish soldier was also reportedly injured in the attack.
CENTCOM confirmed that three soldiers had been killed later in the night, adding that "the attack is under investigation by the Coalition and Iraqi Security Forces. Camp Taji is an Iraqi base that hosts Coalition personnel for training and advising missions. Approximately 18 107mm Katyusha rockets struck the base. The Iraqi Security Forces found a rocket-rigged truck, a few miles from Camp Taji."
According to a-Sharq al-Awsat reporter Charles Lister, the attack was perpetrated by the Iranian-backed Popular Mobilization Forces. About a dozen coalition members were injured in the attack, US officials reported.
Camp Taji, a base holding US troops, has been hit in the past by Katyusha rockets fired by Iranian-allied militias, including Kataeb Hezbollah – an Iraqi branch of the Lebanese Shiíte terrorist organization.
Shortly after the attack, Al Arabiya reported that sites belonging to the PMF were being shelled in eastern Syria, near the border with Iraq. The Syrian state news agency SANA  reported airstrikes in the Albukamal area in Deir Ezzor in eastern Syria on Wednesday night.
The Syrian Observatory for Human Rights (SOHR) reported strikes on the Iranian-controlled Imam Ali base and Al-Hassyan area in the Albukamal area. At least 10 explosions were reported. About 18 Iraqis were killed in the airstrikes in eastern Syria, according to the SOHR.
A US official told Al Hurra that the US would deal with threats in Iraq with appropriate measures.
Iraq's presidency condemned the attack that targeted the Taji military camp, the state news agency said on early Thursday.
'This aggression targets Iraq's security,' presidency added in a statement, stressing the need for an investigation into the attack.
British Prime Minister Boris Johnson issued a statement condemning the attack and added that Foreign Secretary Dominic Raab had spoken with Pompeo.
"We will continue to liaise with our international partners to fully understand the details of this abhorrent attack," Johnson said, without confirming British casualties.
Later on Wednesday night, the US Congress approved a measure limiting President Donald Trump's ability to launch military operations against Iran without congressional approval, according to CNN. Trump is expected to veto the measure. 
The resolution "
directs the President to terminate the use of United States Armed Forces for hostilities against the Islamic Republic of Iran or any part of its government or military, unless explicitly authorized by a declaration of war or specific authorization for use of military force against Iran," according to CNN.
In January, the camp was struck by Iranian ballistic missiles in an attack carried out in response to the assassination of IRGC Quds Force commander Qasem Soleimani. During the attack, a Ukrainian passenger plane was shot down over Tehran. According to Iranian officials, it was mistakenly identified as a cruise missile fired by US forces. 
The crash, killing all 176 passengers and crew, led to mass protests across the Islamic Republic demanding the authorities to provide an explanation of the incident. After the republic's military admitted to shooting down the plane, protests began demanding that Iranian Supreme Leader Ali Khamenei resign.
No organization has taken responsibility for the Wednesday rocket attack as of yet. On Tuesday, ABC News reported that two US troops had been killed in Iraq during an anti-ISIS operation.
According to the report, the US-led coalition in Baghdad said the soldiers were “killed by enemy forces while advising and accompanying Iraqi Security Forces during a mission to eliminate an ISIS terrorist stronghold in a mountainous area of north central Iraq.”
Another four service members were wounded in the operation. The names of the casualties have not been revealed, as the US Defense Department has withheld their publication pending next of kin notification, ABC News reported.
This is a developing story. Reuters contributed to this report.