The strike marked the second time US President Joe Biden has ordered retaliatory attacks against armed groups since he took office.

The United States said on Sunday that it carried out a round of air strikes against Iranian-backed armed groups in Iraq and Syria in response to drone attacks on American personnel and facilities in Iraq, and the militia threatened retaliation.

The US military said in a statement that its targets are combat and weapons storage facilities at two locations in Syria and one location in Iraq. It did not say whether it believed anyone was killed or injured, but the Syrian Observatory for Human Rights, based in the United Kingdom, said at least five fighters were killed and several others were injured.

The attacks were carried out at the direction of President Joe Biden, and this is the second time he has ordered retaliatory attacks against Iranian-backed militias since he took office five months ago.Biden ordered limited bombing of a target in Syria for the last time FebruaryAt that time, it was in response to the rocket attack in Iraq.

The Pentagon said in a statement: “As the strike tonight has shown, President Biden has made it clear that he will take action to protect American personnel.”

Mahmoud Abdulwahid of Al Jazeera in Baghdad said the attack was “significant” and pointed out that the target group threatened to retaliate.

“After this threat, we may see an escalation of military installations,” he said.

Even if the Biden administration is seeking potential attacks Restart the 2015 nuclear agreement with IranCritics say that Iran is not credible and point out that the drone attack further proves that Iran and its proxies will never accept the US military presence in Iraq or Syria.

Biden and the White House declined to comment on Sunday’s attack.

Lawrence Kolb, the former Assistant Secretary of Defense, said that the attack was “very certain” to be seen as a “notice to Iran” by Biden.

“The first time he used force was about a month after he took office,” Kolb told Al Jazeera. “I don’t think he sent that signal to Iran by accident. In fact, when they were about to conduct the seventh round of negotiations on the JCPOA, the fact that he was doing it was that he said, “Just because we are there, it doesn’t mean So we will ignore it (other issues)”.”

Since the beginning of this year, US interests in Iraq have been attacked more than 40 times. As part of the League of Nations, 2,500 US troops have been deployed to combat the remnants of the Islamic State (ISIS) organization.

The vast majority were bombs targeting logistics convoys, and 14 were rocket attacks, some of which were claimed by pro-Iran factions to force Washington to withdraw all troops.

The attack occurred one day after Iraqi Kurdish officials said that three drones carrying explosives attacked near the northern Iraqi city of Albil, where the United States has a consulate there.

It also happened when Hashed al-Shaabi, a pro-Iranian paramilitary coalition opposed to the US presence in Iraq, held a military parade near Baghdad. Senior officials participated in the military parade.

Two U.S. officials, who asked not to be named, told Reuters that since April, Iran-backed militias have carried out at least five drone attacks on facilities used by U.S. and coalition personnel in Iraq.

The Pentagon stated that the target facility was used by Iranian-backed militias, including Qataibu Hezbollah and Qataibu Said Shuhada.

A defense official said that one of the target facilities was used to launch and recover drones.

The US military used F-15 and F-16 jet fighters in the attack and stated that the pilots returned safely.