I’m sure you’ve heard the news. Dozens of children, women, and men were killed this week from exposure to toxic chemicals in Khan Sheikhoun, a town controlled by armed groups fighting Syrian government forces in northern Syria.

Since then we have been reaching out to speak with victims, their relatives, first responders, and medical personnel to find out exactly what happened. The human toll is devastating.

This morning we reached a young mother who told us that she was sleeping on the first floor of their house with her family when they suddenly heard a loud explosion and the windows blew open. She told us:

Our contacts on the ground are saying that Syrian government planes dropped the chemicals. There are still many unanswered questions. But we won’t stop until we get to the truth.

After six years of conflict — with hundreds of thousands dead and millions displaced — chemical attacks have become a regular occurrence in Syria, despite being prohibited by international law. Our researchers have exposed to the world that Syrian government forces have carried out chemical attacks on numerous occasions, as has the Islamic State.

If this is indeed a large-scale chemical attack, it would be one of the deadliest in the Syrian conflict.

Human Rights Watch is calling on the United Nations Security Council—including Russia and China—to condemn this latest attack, demand that Syria fully cooperate with investigators, and support steps to hold those responsible for these atrocities to account.

As this urgent crisis continues to unfold, we will keep you informed and alert you on ways to take action.

Thank you for standing with us.

Ole Solvang
Deputy Director, Emergencies Division
Human Rights Watch
@olesolvang