Beirut's Mayor Jamal Itani says the losses from the explosion could amount to billions of dollars, and it could take up to a year to rebuild the city.

According to the authorities, the explosion struck with the force of a 3.3-magnitude earthquake, and was felt as far as 240 kilometers away, on the island of Cyprus. 

Specialists at the University of Sheffield say the blast had one tenth of the explosive power of the atom bomb dropped on Hiroshima 75 years ago. 

The Lebanese government says about 2,700 tonnes of ammonium nitrate stored at the port caused the disaster.