At least six people were killed Monday in Syrian regime air strikes on a crowded residential area in the last opposition-held stronghold of Idlib in the northwest. First responders known as White Helmets said five women and a child were killed. Rescue workers were still searching for survivors under the rubble after the airstrikes hit in the town of Ariha. Videos from the scene by the White Helmets showed a narrow alley blocked by the debris from a pulverized building. Survivors covered in white dust were among those who lifted a wounded man on a gurney and a young girl into the ambulance. The Syrian Observatory for Human Rights also reported six killed. Fawaz Hilal, head of the “Salvation Government” that runs Idlib province, expressed confidence that opposition fighters gathered in the Idlib region from all over Syria would be able resist the onslaught. “This ferocious attack is a bone-breaking battle. If the regime is able to break our defensive lines in northern Hama and southern Idlib it will not stop until it reaches the borders,” Hilal told Reuters in an interview. His government, backed by the powerful Tahrir al-Sham group, had called on its employees to help shoulder the “military burden” through building sandbag defenses, manning front lines, financial support or any other help. “We are all concerned with repelling this attack,” he said. The scene in Ariha was reminiscent of the violence that has hit many opposition-held areas as the regime pursued similar military tactics to regain control of territory it had lost to armed opposition. Idlib is home to nearly 3 million people, who have nowhere to run to escape the regime offensive after they were displaced from other parts of Syria to escape similar regime assaults in the past three years. A ceasefire in place since September, negotiated by Russia and Turkey, has all but collapsed. UN agencies say more than 200,000 are displaced within the stronghold, moving from the southern tip up north and crowding already packed camps and towns. Most of those displaced are living outside of camps, the UN said, while some have sought safety near the Turkish border where they hope no airstrikes would pursue them there. Some 20 health facilities, three displaced peoples camp and one refugee camp were hit in the violence, the UN Office for the Coordination of Humanitarian Affairs reported on Friday. Since the violence picked up on April 30, the Observatory said at least 215 civilians, including 47 children were killed in Idlib. In adjacent regime areas, 21 civilians were killed by opposition fire, according to the Observatory which monitors the war. On Monday alone, the Observatory said there were more than 100 air raids and as many as 93 barrel bombs dropped on the southern section of Idlib. Russia and the regime announced last week the opening of two corridors for civilians to exit the opposition-held enclave— another familiar tactic followed to empty opposition areas amid a military operation. The UN said it was not party to discussions for such a corridor and said movement of civilians must be a choice, not forced by violence.