Russia accused the United States on Sunday of breaching agreements when it carried out airstrikes on Syria’s Idlib region a day earlier.
On Saturday the US Central Command, part of the Department of Defense, had said that US forces struck an al-Qaeda facility north of Idlib in Syria in an attack aimed at the organization’s leadership.
TASS news agency, citing the Russian defense ministry, said Washington had forewarned neither Russia nor Turkey about the strikes. It added that Russian and Syrian regime warplanes had not carried out raids in the region recently.
The Syrian Observatory for Human Rights said airstrikes pounded bases belonging to extremist fighters in Syria’s northwest.
The UK-based monitor said the strikes, near the town of Maarat Misrin in Idlib province, killed more than 40 militants, including some commanders.
Interfax news agency cited Russian military as saying that the United States carried out airstrikes in the region between Maarat Misrin and Kafer Haya in Idlib on Saturday.
US airstrikes have hit a number of Nusra commanders in northwest Syria in recent years.
Syrian regime airstrikes on the extremist-run Idlib region had stopped on Saturday, after the regime agreed to a Russia-backed ceasefire following four months of deadly bombardment, the monitor said.
The Idlib ceasefire brings temporary respite after a crushing offensive by Syrian troops in the last remaining opposition stronghold in the country. The offensive began April 30 and intensified in recent weeks, forcing hundreds of thousands to flee, many of whom were already displaced.
The UN said more than 450 civilians have been killed.
A similar ceasefire at the beginning of the month lasted a few days, after which the regime assault resumed and forces captured the Idlib town of Khan Sheikhoun and all opposition-held towns and villages in nearby Hama province.