At least 157 people have died in Beirut port blast, Lebanese health ministry reported.

The number of victims is expected to increase, as dozens of victims are considered missing after the explosion, BBC reported.

The Lebanese government announced that it had placed some port officials responsible for the storage and security of warehouses under house arrest pending the results of an investigation.

The government gave the investigating committee four days to identify those responsible for the devastating explosion, Foreign Minister Charbel Vehbe told a French radio station.

Hundreds have been reported missing. Over 300,000 people have been displaced from their homes.

Beirut is declared a "disaster city" and a two-week state of emergency has been imposed.

It is still unclear what exactly caused the blast. According to Lebanon's PM, an investigation would focus on an estimated 2,750 metric tons of the explosive ammonium nitrate stored at a warehouse.