Al-Jazeera correspondent in Syria said that the fourth zone of de-escalation in northern Syria is witnessing a calm and anticipated calm after Russia announced a unilateral ceasefire in the region as of this morning.

The correspondent monitored some violations by regime forces, which were bombarded with heavy artillery in the towns of Jergnaz and Deir Sharqi in the southern countryside of Idlib.

The spokesman for the National Liberation Front of the opposition Captain Naji Mustafa in a statement to the island they do not trust the commitment of the Syrian regime and its Russian ally to declare a ceasefire.

The Russian army announced on Friday a unilateral ceasefire committed by the Syrian army, to enter into force on Saturday morning in the Idlib area.

Damascus agreed to a cease-fire, according to the official Syrian news agency (SANA) quoted a military source, with the army retained the "right of reply" to any breach.

This development comes after an escalation witnessed by Idlib in recent days, where 13 civilians were killed yesterday, including five children, and dozens were injured by raids by Syrian regime warplanes on residential neighborhoods in the city of Ma'rat Al-Nouman in the southern countryside of Idlib.

System control
Syrian regime forces have taken control of several towns and villages in Hama and Idlib, northern Syria, as part of their operations, which began on April 25 with the support of the Russian Air Force.

During their advance in Khan Sheikhoun and the northern countryside of Hama last week, regime forces cordoned off a Turkish observation post in the town of Mork, the largest of 12 such points Ankara has deployed in Idlib and its environs under the agreement with Russia.

The United Nations on Wednesday expressed concern about attacks by the Syrian regime and Russia on Idlib and neighboring areas since the end of April, noting that it led to the deaths of 550 civilians and the displacement of 400 thousand others, as well as the settlement of dozens of towns and villages to the ground.