Rojekê Piştî Êrîşa Gazên Kîmyayî li Kahn Sheikhoun(Xan Şeyxûn) li Sûriyê

A Syrian man collects samples from the site of a suspected toxic gas attack in Khan Sheikhun, in Syria’s northwestern Idlib province, April 5, 2017.

A Syrian man collects and bags the body of a dead bird, reportedly killed by a suspected toxic gas attack in Khan Sheikhun, April 5, 2017.

A general view shows damage at a site hit by airstrikes on Tuesday in the town of Khan Sheikhoun in rebel-held Idlib, April 5, 2017.

Empty tables sit in St. Mark's square in Venice, Italy. Italy has been scrambling to check the spread of Europe's first major outbreak of the new viral disease amid rapidly rising numbers of infections and calling off the popular Venice Carnival and closing tourist attractions.

A still image taken from a video posted to a social media website on April 4, 2017, shows people lying on the ground, said to be in the town of Khan Sheikhoun, after what rescue workers described as a suspected gas attack in rebel-held Idlib, Syria.

A still image taken from a video posted to a social media website on April 4, 2017, shows a man lying on the ground and being sprayed with water, said to be in the town of Khan Sheikhoun.

A civil defense member breathes through an oxygen mask, after what rescue workers described as a suspected gas attack in the town of Khan Sheikhoun, April 4, 2017.

Men ride a motorbike past a hazard sign at a site hit by an airstrike on Tuesday in the town of Khan Sheikhoun, April 5, 2017. The hazard sign reads, "Danger, unexploded ammunition."