Massive explosions in Lebanon's capital city of Beirut, a Mediterranean coastal country, appear to have originated from the explosive substance ammonium nitrate.

Two explosions occurred at the port in Beirut on the afternoon of the 4th, local time, which severely damaged the port and destroyed nearby buildings.

So far, at least 73 people have been killed and 3,700 wounded, according to the Lebanese Ministry of Health.

Lebanese Prime Minister Hassan Diab said in a news conference, "about 2,750 tons of ammonium nitrate have been stored in the Beirut harbor warehouse for six years."

Ammonium nitrate, an agricultural fertilizer, is used as a basic raw material for inorganic manufacturing such as gunpowder.

During the explosion in Yongcheon Station in North Korea in April 2004, it was estimated that an explosion occurred due to ammonium nitrate leakage.