Updated at 8:45 a.m. ET Wednesday
Poisonous chemicals are suspected of augmenting an aerial bombardment of a rebel-held town in Syria's Idlib province Tuesday, with the Syrian Observatory for Human Rights saying at least 20 children were among those who died. The group says the initial death toll of 58 has risen to 72, and that all the victims were civilians.
The attack was reportedly carried out in Khan Shaykhun, a town in northwest Syria that sits about halfway between Homs and Aleppo on the country's main north-south highway.