A Syrian official and the state news agency say more than 100 people have been treated at hospitals after a suspected poison gas attack by rebels in the northern city of Aleppo, updating an earlier toll.

Forensic Medicine General Director Zaher Hajo told The Associated Press Sunday that those wounded the night before were taken to two hospitals in Aleppo, Syria's largest city.

Hajo says all but 15 of the 105 people who were treated have been discharged. He says two people who were in critical condition have improved.

The Britain-based Syrian Observatory for Human Rights says 94 people were treated, with 31 remaining in hospitals.

Rebel commanders and opposition figures denied carrying out a chemical attack and accused the government of trying to undermine a cease-fire.