According to opposition groups, the Syrian government conducted airstrikes and dropped its notorious mass-casualty “barrel bombs” on the city of Daraa on Wednesday. Daraa is located in a region classified as a “safe zone” under Russia’s latest peace plan.

“The Britain-based Syrian Observatory for Human Rights said government forces carried out at least 12 airstrikes and dropped at least nine barrel bombs on rebel-held parts of Daraa as intense clashes with insurgents, including members of the al-Qaeda-linked Levant Liberation Committee, continued in the city’s Manshiyeh neighborhood,” reports the Associated Press. “The monitoring group added that at least two rockets were launched by government forces in the area.”

The Syrian government claims the airstrikes were launched in retaliation for rebel forces breaching a ceasefire agreement to attack Syrian Arab Army positions.

The Russian plan for “safe zones” or “de-escalation zones” has not been finalized yet, but maps of the safe areas are expected by June 4, according to the AP.

The Syrian Observatory for Human Rights also believes an airstrike from the U.S.-led anti-ISIS coalition in a rural area near the besieged Islamic State capital of Raqqa killed “at least 16 civilians, including five children from the same family.”

Another activist group, Raqqa Is Being Slaughtered Silently, said the 16 victims were “were mostly from the same family and have been displaced from another area south of Raqqa controlled by ISIS.”

“Our goal has always been for zero civilian casualties, but the Coalition will not abandon our commitment to our partners because of ISIS’s brutal tactics terrorizing civilians, using human shields, and fighting from protected sites such as schools, hospitals, and religious sites,” coalition officials said in response to this report.

Syria’s military claimed on Wednesday to have killed Abu Musab al-Masri, the Islamic State’s self-styled “minister for war” in Syria, along with a dozen other senior ISIS commanders. According to the report, these high-value targets were killed sometime over the past two weeks.

As an ISIS expert told Reuters, al-Masri’s death would be a “significant blow” to the Islamic State ahead of the battle for Raqqa.