US jets attacked a convoy of forces loyal to Syrian dictator Bashar Assad in southern Hama governorate May 18—ironically within one of the "deconfliction zones" established by the US and Russia. The convoy was apparently approaching the base at al-Tanf, which is used by FSA forces and US advisors. "We notified the coalition that we were being attacked by the Syrian army and Iranians in this point, and the coalition came and destroyed the advancing convoy," said Muzahem al-Saloum of the local FSA militia, Maghawir al-Thawra (also rendered Maghaweer al-Thawra). The pro-Assad militia targeted in the raid was named as Saraya al-Areen, apparently an Alawite force commanded by Iranian Revolutionary Guards. The regime was also said to be moving Hezbollah and Iraqi Shi'ite paramilitary forces into the area.

Said US Defense Secretary James Mattis: "No. We are not increasing our role in the Syrian civil war. But we will defend our troops." (EA Worldview, BBC News, Al Masdar, CBS)

This constitutes the second US air-raid targetting Assad forces, following last month's strikes on Shayrat air-base outside Homs. Assad forces were also accidentally hit by US forces in Deir al-Zour governorate last September.