An airstrike in eastern Syria killed eight fighters of Iraq's paramilitary Popular Mobilisation Forces (PMF) overnight, the Syrian Observatory for Human Rights said Friday (January 10th).

"Unidentified aircraft targeted vehicles and arms depots in the Albu Kamal area, causing a large explosion," said Observatory head Rami Abdel Rahman.

At least eight Iraqi PMF fighters were killed, and several others were wounded, he said.

The international coalition that has been battling the "Islamic State of Iraq and Syria" (ISIS) on Friday denied carrying out the strike.

Abdel Rahman said three villages in the Albu Kamal area known for housing forces loyal to Tehran have been targeted by drone strikes since Wednesday.

The deadly strike comes in a context of spiralling tension between the US and Iran, much of which has played out in Iraq.

Late last year, a US airstrike in Iraq killed 25 PMF fighters from the Iran-aligned Iraqi militia Kataib Hizbullah, considered one of the closest to Tehran.

Supporters of Iran-aligned Iraqi militias subsequently stormed the huge US embassy compound in central Baghdad, further escalating the situation.

Saudi Arabia condemns Iran strike

On January 3rd, a US strike near Baghdad airport killed Islamic Revolutionary Guard Corps Quds Force (IRGC-QF) commander Qassem Soleimani, along with Abu Mahdi al-Muhandis, a founder of Kataib Hizbullah.

Tehran has vowed bloody revenge and has so far responded with ballistic missiles on a base in western Iraq housing US and other coalition troops.

Saudi Arabia on Thursday condemned "Iranian violations of Iraqi sovereignty", said a statement carried by Saudi Press Agency following Wednesday's retaliatory strikes by Iran.

The attack has been denounced by the Iraqi prime minister, the foreign ministry and Iraqi President Barham Saleh as a violation of the country's sovereignty.