Ammonium nitrate stored in a warehouse linked to catastrophic Beirut explosion - CNN

The secretary-general of the Lebanese Red Cross, Georges Kettaneh, told Lebanon's National News Agency Wednesday that at least 100 people have been killed, saying the disaster is "unprecedented and very large."

The organization said it has set up multiple temporary shelters with food, hygiene kits and basic needs to receive 1,000 families who have lost their homes.

Tuesday's explosion in the Lebanese capital resulted in an estimated US$3-5 billion worth of damage, Beirut governor Marwan Abboud told reporters Wednesday.

Prime Minister Diab has launched an investigation into the blast, saying he "will not rest until we find those responsible for what happened, hold them accountable, and impose maximum punishment."

Ammonium nitrate is a highly volatile material that's used in agricultural fertilizer and high-grade explosives.

Following Tuesday's explosion, the United States Embassy in Beirut urged those in the area to "stay indoors and wear masks if available" due to reports of toxic gases released from the blast.

One resident said the scenes looked "like an apocalypse," another said the port was "totally destroyed."

"You can see injured people all over the streets in Beirut, glass all over the place, cars are damaged," said Bachar Ghattas, another resident.

All its ambulances across the entire country were dispatched to the capital to support with the rescue and evacuation of patients.

The Philippine Embassy in Beirut on Wednesday confirmed that two of its citizens died in the explosion.

Two of the injured were part of a group of 13 Filipino seafarers whose ship was docked "some 400 meters away from blast zone," said the Embassy, who added that the other 11 have been reported as missing.

Australian Prime Minister Scott Morrison said at least one Australian was killed in the blast and the Australian Embassy building has been "significantly compromised."

Among the injured are six Turkish citizens, a Chinese citizen, a Japanese national and an Indonesian, according to their respective governments.

South Korea's foreign ministry said its embassy in Beirut sustained minor damage but had not received any reports of South Korean victims.