The US says it has carried out an attack on leaders of a group it calls al-Qaeda in Syria, in the country's rebel-held Idlib province.
US Central Command said the operation had targeted those “responsible for attacks threatening US citizens, our partners and innocent civilians”.
No details were given but other reports say some 40 people died in a missile strike on a jihadist training camp.
It was hit just after Syrian government forces began a truce in Idlib.
Initial reports indicated that calm had settled on the front lines after the Russian-backed unilateral ceasefire, which started at 06:00 (03:00 GMT).
Turkish threat
In a separate development, Turkey warned it would launch an operation to set up a “safe zone” in north-eastern Syria if talks with the US on the issue failed.
“Within a few weeks if our soldiers do not start to actually control this area, there will be no other option left but to implement our own operation plans,” Turkish President Recep Tayyip Erdogan said.
Ankara and Washington are at loggerheads odds over the future of the region where the US-backed Kurdish YPG militia has been fighting so-called Islamic State.
Turkey considers the YPG a terrorist group.
Earlier this month, the Kurdish-led authorities in north-eastern Syria reportedly began withdrawing…
