by Helen Corbett, dpa

Iraq/Syria – At least seven pro-Iranian Iraqi militiamen were killed in US airstrikes on the Iraqi-Syrian border, a UK-based monitoring group said on Monday.

The US Pentagon said on Sunday that President Joe Biden had ordered the airstrikes against Iran-backed militia groups in the border region.

The facilities were used by Iran-backed militias engaged in drone attacks against US personnel and facilities in Iraq, Pentagon press secretary John Kirby said.

Two locations in Syria and one in Iraq – both close to the border between the two countries – were targeted.

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The Britain-based Syrian Observatory for Human Rights said that in addition to those killed, others were injured, and they were mainly affiliated with Iraq's Popular Mobilization Forces, also known as the Hashd al-Shaabi.

The strikes targeted posts in Syria's eastern countryside of Deir al-Zour province, the Observatory said. Hashd al-Shaabi sources told dpa that at least four fighters were killed.

Ahmed al-Maksusi, a Hashd Shaabi commander, did not specify the number of those killed. He vowed in a statement that his forces would await orders "to respond and take revenge."

The Pentagon said the locations were operational and weapons storage facilities used by several Iran-backed groups including Kata'ib Hezbollah and Kata'ib Sayyid al-Shuhada.

"As demonstrated by this evening's strikes, President Biden has been clear that he will act to protect US personnel. Given the ongoing series of attacks by Iran-backed groups targeting US interests in Iraq, the president directed further military action to disrupt and deter such attacks," Kirby said.

In his first order for a military retaliation as president in February, Biden ordered strikes on Iranian-backed militant groups in eastern Syria in response to rocket attacks against US and coalition personnel at a base in Iraq.