Syrian Observatory for Human Rights (SOHR) reported that Russian warplanes carried out airstrikes in southern Syria, violating one of the so-called "de-escalation zones".
“For the first time since the ceasefire in southern Syria was agreed last year, intense Russian air strikes hit cities in the eastern part of Daraa province," said the head of the UK-based Syrian Observatory for Human Rights, Rami Abdel Rahman.
According to Reuters, the two monitoring centers controlling the movement of military aircraft recorded at least 20 strikes in the city of Busra al-Harir in the northeast of Daraa province.
Sources in the Syrian opposition said that Russian aircraft hit the rebels in south-west Syria in on June 24, providing air cover for the Syrian military trying to capture the strategic area near border with Jordan and the Golan Heights.
There has been no official confirmation from the Kremlin yet.
Russia, together with Iran, supports Syrian President Bashar al-Assad in the Syrian conflict, providing air cover for government troops.
U.S. Ambassador to UN Nikki Haley noted that the Syrian military operation "clearly violates the ceasefire in de-escalation zone", and intense bombardments forced more than 11 000 civilians to flee their homes.
Earlier, the US warned Russia and Damascus of ‘serious repercussions’ if ceasefire in Daraa de-escalation zone continues to be violated.
“The U.S. remains troubled by reports of increasing Syrian regime operations in southwest Syria within boundaries of de-escalation zone negotiated between U.S., Jordan and Russia. U.S. continues to warn both Russia and the Assad regime of the serious repercussions of these violations,” wrote the US state department spokesperson, Heather Nauert, on Twitter.
The agreement to create a de-escalation zone in south-west Syria was reached in Hamburg on July 7, 2017. According to the agreement, the ceasefire in the Syrian provinces of Daraa, Quneitra and As-Suwayda entered into force on July 9, 2017.