US warplanes launched new air strikes on Saturday on military points of pro-Iranian militias in eastern Syria, in response to rocket attacks and suicide drones on US bases on Friday night.

This comes as the Syrian Observatory for Human Rights reported on Saturday that the death toll of pro-Iranian militias as a result of US raids in eastern Syria rose to 19, including members of the regime forces, while the US army announced that it had transferred its wounded soldiers to Iraq for treatment.

Al Jazeera's correspondent quoted a US military official as saying that US forces in eastern Syria were attacked separately Friday night with rockets and suicide drones, which resulted in the injury of a US soldier.

The US official explained that just before 11:00 pm local time in Syria, the "Conoco" base of the coalition forces was attacked by a missile, which resulted in the injury of a US soldier in stable condition.

He added that the "Green Village" base in eastern Syria was also attacked by 3 suicide marches just before midnight, stressing that US air defenses managed to shoot down two of them, while the third hit the base and damaged a building without causing injuries.

After the attack, US warplanes launched airstrikes on military points of pro-Iranian militia positions in Deir Ezzor and the areas of Albu Kamal and Al-Mayadeen in the east, according to the Syrian military opposition's air observatory.

In a related context, the US military announced that it sent 6 of its soldiers and a contractor who were wounded in rocket attacks that targeted its bases in Syria to Iraq for treatment.

U.S. Central Command spokeswoman Abigail Hammock said in a statement that the condition of the six soldiers wounded in the attack was stable and two of them had returned to work.

She explained that a soldier and a contractor were treated in Baghdad, while two other soldiers are being treated in Erbil, noting that the injured who were treated in Baghdad will be sent to the United States soon to follow up on their health status.

The London-based Syrian Observatory for Human Rights said in a press release Saturday that the US raids killed 11 Syrians working within the pro-Iranian militias, in addition to 3 members of the regime forces, and 5 pro-Iranian militias of non-Syrian nationalities.

He explained that the death toll is likely to rise because there are wounded, some of them seriously, in addition to information about other deaths.

Biden's Comment

In his first comments on the events, US President Joe Biden declared on Friday in Ottawa that the United States does not seek conflict with Iran, but is ready to act aggressively to protect its people.

Biden said during a joint news conference with Canadian Prime Minister Justin Trudeau: "I gave my instructions to respond quickly after the attack on our forces Thursday in Syria by Iranian-backed groups."

Commenting on the U.S. airstrikes in Syria, House Armed Services Committee Chairman Mike Rogers said the IRGC and its proxies are "terrorists" seeking to harm Americans and undermine U.S. national security.

He added that the response in Syria is "a warning to any terrorist that he will face a swift and decisive response when he attacks US forces."

Rogers said in a statement that U.S. operations against groups linked to the Revolutionary Guards, including Thursday's strike, are an important component of counterterrorism efforts.

Meanwhile, the New York Times quoted U.S. officials as saying that the main air defense system at the coalition base in northeastern Syria was not fully operational when the base was attacked by an Iranian-made drone.

The newspaper added that an investigation has been launched to find out why the system is not fully operational, and the extent to which this affects the base's defenses.

It was also unclear whether the attackers discovered the vulnerability or if the march was dispatched, the newspaper's sources said.

Rising tension

Tensions in Syria between the United States and Iran-backed military groups have risen to a record high in recent hours.

The new round of escalation began when a march coming from Iraq targeted the Kharab al-Jir base of the international coalition in the countryside of Hasaka on Thursday, killing an American contractor and wounding 6 soldiers.

In response, US warplanes bombed sites belonging to the Iranian militias, after midnight Thursday and dawn on Friday, targeting a weapons and ammunition depot in the grain center and the rural development center opposite the officers' housing in the Harabish neighborhood of Deir Ezzor city, and other sites in the Albu Kamal desert and the outskirts of the southern squares, causing deaths and injuries in addition to material losses.

Iran-backed groups, according to US officials, have carried out 78 attacks on coalition forces in Syria since 2021, and the means of attack varied between drone bombs to rockets and mortars.

Syrian sources estimate the presence of about 15,<> fighters from Iraqi, Afghan and Pakistani groups loyal to Iran in the oil-rich province of Deir Ezzor, specifically in the area between the border cities of Albu Kamal and Deir Ezzor through Al-Mayadeen.

The bases and centers where US forces are present are scattered in the areas of southeastern Syria where the Al-Tanf base was established, as well as to the northeast of this country, specifically near Hasaka and Deir Ezzor.

U.S. estimates speak of the presence of about 900 to two thousand American troops in a strip of about 55 kilometers.