The US launched airstrikes on two sites in eastern Syria linked to the Islamic Revolutionary Guard Corps, Defense Secretary Lloyd Austin said Thursday.

"The precision self-defense strikes are a response to a series of ongoing and mostly unsuccessful attacks against US personnel in Iraq and Syria by Iranian-backed militia groups that began on October 17," he said in a statement.

"If attacks by Iran's proxies against US forces continue, we will not hesitate to take further necessary measures to protect our people."

Airstrikes target ammunition storage facilities

The airstrikes happened at about 4:30 a.m. local time (0130 GMT) on Friday near Abu Kamal, a Syrian town bordering Iraq. US F-16 fighter jets struck weapons and ammunition storage facilities, a senior US official told news agency AP on the condition of anonymity.

President Joe Biden authorized the strikes with the aim of deterring future threats. The last week has seen escalating drone and missile strikes on US bases and personnel in the region.

Air Force Brig. Gen. Pat Ryder said there have been at least 19 attacks on US bases in Syria and Iraqsince October 17.

According to the Pentagon spokesperson, drones targeting al-Asad Airbase in Iraq and al-Tanf Garrison in Syria injured 21 US personnel.

"I think we've been crystal clear that we maintain the inherent right of defending our troops and we will take all necessary measures to protect our forces and our interests overseas," Ryder said.

The strikes came a day after President Biden's warned to Iran's Ayatollah Ali Khamenei against attacks on US forces.

Strikes not linked to Israel-Hamas war

The US maintains that its strikes are in response to attacks on its troops and not connected to the war between Israel and Hamas.

It accuses Tehran of backing proxies attacking American forces.

Meanwhile, Iranian authorities have criticized the US for supplying weapons to Israel, leading to civilian casualties in Gaza.

The US has 900 troops in Syria, and 2,500 in neighboring Iraq, to support local forces against a resurgence of the Islamic State.

ss/rc (AP, AFP, Reuters)