Aid agencies say a deal has been reached to allow them to send food and medicine into besieged towns in Syria. Tens of thousands of people are reportedly in danger of starving to death if aid does not reach them soon.

The deal agreed on Saturday will result in humanitarian supplies being sent to the opposition-held town of Madaya at the Lebanese border, as well as two villages in the northwestern province of Idlib, which are blockaded by rebel forces.

According to Al Jazeera, aid agencies have warned of widespread starvation in Madaya, where some 40,000 people are currently at risk.

The UN said on Thursday that Damascus had agreed to allow access to all three areas, but failed to say exactly when and where the deliveries would take place.

“Both date and time have been set. Aid will go to three towns on Monday morning, all at the same time,” a source familiar with the matter said and a pro-Syrian government source confirmed the details.

The volunteer-run Syria Civil Defense told Al Jazeera that Saturday’s Russian air strikes targeted the town of Maarat al-Numaan, 290 km north of Damascus, and that at least 43 people were killed and 150 others wounded. “Many of those injured are in very serious conditions, the death toll is expected to rise,” he added.

Anas Maarawi, a media activist in Idlib, informed Al Jazeera that the attacks targeted a court and a prison controlled by the Islamist al-Nusra Front in Maarat al-Numaan. “The first floor of the court was targeted in addition to a prison. We are getting reports that at least 53 have been killed in these air strikes,” Maarawi said.