BEIRUT, Lebanon — Syria called on the United Nations on Sunday to condemn its rebel foes after an apparent attack with unidentified chemicals in the city of Aleppo sent scores of choking victims to hospitals.

Medics reported a flood of patients with breathing troubles, inflamed eyes and other symptoms after a shelling attack on Saturday that Syrian and Russian officials blamed on the rebels.

The Syrian state news service, SANA, said that more than 100 people had been affected by the attack, although it reported no deaths. The Syrian Observatory for Human Rights, a monitoring group based in Britain, released slightly lower numbers. A spokesman for Russia’s Ministry of Defense said 46 people, including eight children, had been exposed to chemicals.

It was not immediately clear who had launched the attack on Saturday or what substance was used. Syria’s dwindling rebel movement is a patchwork of factions with no central command. A few rebel groups denied the government’s accusations.