The wife, daughter, and some advisers of Lebanese Prime Minister Hassan Diab were slightly injured in the explosion in the port of Beirut, Forbes reported, citing the Lebanese Broadcasting Corporation International.
The blast was so powerful that it was heard and felt in Cyprus, too.
The Lebanese interior ministry said that ammonium nitrate had exploded in the port of Beirut.
According to some reports, there was a short circuit in a warehouse, which caused a fire, as a result of which the nitrate exploded.
According to the latest figures, 50 people have been killed and more than 2,700 injured, but the country's authorities fear the death toll could rise.
Some people are still trapped under the rubble.
Local hospitals are overcrowded.
Lebanese Prime Minister Hassan Diab has declared August 5 a day of national mourning.