BEIRUT, Lebanon — Insurgent shelling hit a maternity hospital in the government-held section of the Syrian city of Aleppo on Tuesday, according to state media and footage from the scene, underscoring what rights groups are calling a growing disregard for the rules of war.

It was the sixth assault on a medical facility in the divided city in less than a week and the first to have caused casualties on the government-controlled side. At least three women were reported killed and 17 people wounded, including children.

On Wednesday, warplanes destroyed a pediatric hospital and a clinic on the rebel-held side of the city, leaving dozens of people dead, including medical workers, women and children.

That attack, believed to have been carried out by the Syrian government despite its denials, came as intensifying airstrikes and rebel shelling shattered what remained of a fragile truce that had prevailed for a few months. The violence of the past week has plunged Aleppo back into all-out war, killing scores of people, mainly civilians.