Parts of the central district were set ablaze and protesters took over at least one government ministry, declaring it the "headquarters of the revolution."

Protesters occupied a foreign affairs ministry building and set at least one government office on fire, throwing documents out of the window, as unrest spread through the city.

More than 100 people have been injured in the protests, including 22 who were transferred to hospitals, according to the Lebanese Red Cross.

"You survive an explosion in Beirut only to be teargassed," said one man in his 20s as he held an onion to his mouth to mitigate the effects of the gas.

Protesters held signs reading, "Here is where the nooses should be hung." The mock gallows have become a key symbol of the demonstrations, which are demanding that those responsible for the Tuesday's blast are held accountable, as well as against corruption and mismanagement of the country.

The gallows were erected in the same place where several people were hanged more than 100 years ago by the then ruling Ottoman Empire for revolting against Istanbul.

Some protesters occupied a Foreign Affairs Ministry building in eastern Beirut, unfurling a large banner over its severely damaged structure that called for the disarmament of Hezbollah, the Iran-backed Lebanese armed group and political party, according to Lebanese TV channel LBCi.

One of the demonstrators declared the building the "headquarters of the revolution," through a megaphone.

Lebanon was already embroiled in an economic meltdown prior to Tuesday's blast which obliterated its main port, destroying grain silos.

Authorities have detained 16 people in connection with the blast, including Director General of Lebanese Customs, Badri Daher, the head of Beirut Port, Hasan Kraytem and the former head of customs Chafic Merei.