Lebanese President Michel Aoun called for an emergency cabinet meeting on Wednesday and said a two-week state of emergency should be declared following a massive explosion in Beirut that killed at least 100 people and injured 4,000 others.

The explosion on Tuesday sent shockwaves across the city, causing widespread damage as far as the outskirts of the capital.

Officials said they expect the death toll to rise further as emergency workers dig through the rubble to search for survivors.

Beirut’s city governor Marwan Abboud said up to 300,000 people have lost their homes and authorities are working on providing them with food, water and shelter.

The cause of the explosion was not immediately clear. Officials linked the blast to some 2,750 tonnes of confiscated ammonium nitrate that were being stored in a warehouse at the port for six years.

Aoun assembled the country’s High Defence Council following the explosion.

Prime Minister Hassan Diab called for a day of mourning on Wednesday.

The Lebanese cabinet has decided to place port officials under house arrest until investigations determine who is responsible for the blast, a governmental source told Al Jazeera following an emergency session. 

An official announcement is expected to be made shortly. 

It was not clear how many officials would be included or their seniority level. According to Reuters news agency, the army will oversee the house arrest of the officials who have overseen storage and security since 2014.