A wave of late night airstrikes pummeled the northwestern Syrian city of Idlib, killing at least 23 people, wounding dozens and trapping several under the rubble of their homes, opposition activists said Tuesday.

At least seven children were among those killed in the strikes, said the Britain-based Syrian Observatory for Human Rights, a monitoring group that relies on local activists.

The Observatory said Russia carried out the airstrikes on the city, which is controlled by several insurgent groups, including a local al-Qaida affiliate known as the Nusra Front, but Moscow denied any involvement.

“The Russian aviation hasn’t performed any combat tasks, moreover hasn’t conducted any airstrikes in the province of Idlib,” the Russian Defense Ministry spokesman, Maj. Gen. Igor Konashenkov, said in a statement Tuesday.

Since the Russian military campaign began last September in an effort to shore up Syrian President Bashar Assad’s forces, Moscow has staunchly denied striking any civilian areas.

The Nusra Front has evacuated all its civilian centers, such as religious courts, in the city of Idlib and nearby villages and towns, said an activist based in Idlib province who goes by the name of Ahmad Ariha. He said the air raids late Monday killed and wounded some 250 people.

A Syria-based reporter for Al-Mayadeen TV, an Arab News channel based in Beirut, said the airstrikes targeted a Nusra Front meeting.

A Syrian opposition figure said the airstrikes “demolished” three centers for the Army of Conquest, a coalition of several militant factions including Nusra Front and the powerful ultraconservative Ahrar al-Sham group. The opposition figure said more than half of those killed in Idlib on Monday were fighters.

The person spoke on condition of anonymity since revealing the target might anger other opposition groups.

The Local Coordination Committees, another activist group that monitors the war, said the airstrikes hit two hospitals. It said 50 people were killed and over 200 were wounded. Different tolls are common in the aftermath of big attacks.

The Observatory said about 10 air raids targeted areas near the National Hospital, the Al-Jalaa public gardens and other neighborhoods in Idlib.

“The air raids either aim to pave the way for a ground offensive on Idlib or to make the resistance kneel,” said Turkey-based activist Hassan Dughaim, who is originally from Idlib and is in contact with residents in the province that borders Turkey. “Some people are fleeing the city but the bombing is chasing them. People are even getting bombarded in refugee camps.”

Dughaim, the Observatory and the LCC all reported airstrikes on towns and villages near Idlib. Ariha, the Syria-based activist, said fresh air raids on Tuesday destroyed two vaccination centers in the village of Kfar Takharim.

Amateur videos showed relief workers using flashlights as they dug through the rubble at night. When a boy is seen being carried out alive, shouts of “God is great’ can be heard in Arabic. Another video shows a man being carried into an ambulance.

The videos appeared genuine and corresponded to AP reporting.

(AP)