Beirut explosion: What is ammonium nitrate and why is it deadly?

The explosion in Lebanon yesterday.

The blast which killed at least 100 people and injured more than 4,000 others in the Lebanese capital, Beirut, is thought to have been caused by a chemical commonly used in fertilisers.

Lebanon President Michel Aoun said that 2,750 tonnes of ammonium nitrate being stored unsafely in a warehouse caused the explosion.