Lebanon’s parliament speaker has called for quickly forming a new government in the first legislative session since the catastrophic explosion that killed 172 people last week and pushed the cabinet to resign.

Security forces were heavily deployed in the capital Beirut on Thursday, stopping protesters from reaching a conference centre where MPs convened.

Many Lebanese are furious at a long-entrenched political class they blame for the blast, accusing them of endemic corruption, mismanagement and negligence.

Senior US diplomat David Hale is expected in Beirut later on Thursday to stress the urgent need for financial reforms, and stamping out graft, among other messages, the US Embassy said.

This striking footage shows a woman in Beirut hitting a tear gas canister with a tennis racket as protesters clash with security forces. Anti-government sentiment in Lebanon continues after the devastating explosion that killed at least 200 people last week pic.twitter.com/k8ty7qSe9L

— NowThis Impact (@nowthisimpact) August 13, 2020

The August 4 blast at a warehouse containing highly-explosive ammonium nitrate in Beirut port injured some 6000 people, left around 300,000 without habitable housing and wrecked swathes of the city, which was already in a deep financial crisis.

Roads to the UNESCO Palace on the southern outskirts of the capital, where parliament has met during the COVID-19 pandemic, were blocked with metal gates ahead of the protest.

Outrage has fuelled protests in which hundreds of people have been injured in confrontations with security forces who fired tear gas.

Parliament approved a state of emergency declared by the now caretaker government. The resignations of eight MPs who quit after the blast was also confirmed.

The scene of an explosion at the Beirut port on August 4. Photo: STR/AFP

State media said Parliament Speaker Nabih Berri, a long-time pillar of the sectarian elite, called at the session for “speeding up the formation of a (new) government”.

But Mr Berri also “wants to give a political message – that parliament exists – despite all this talk about early elections and the resignations of MPs”, a senior political source said.

Humanitarian aid has poured in but foreign countries have made clear they will not provide funds to help Lebanon avert economic collapse without action on long-demanded reforms to tackle state corruption and waste.

Authorities have estimated losses at $US15 billion, a bill Lebanon cannot pay: it already defaulted on its enormous sovereign debt in March. Foreign reserves are critically low, and talks with the International Monetary Fund have stalled.

Politicians are in early consultations on forming a new cabinet, a complicated process in a country riven by divisions and governed by a sectarian power-sharing system.

The government came to office in January with backing from parties including the heavily armed, Iran-backed Shi’ite Muslim Hezbollah. Together with its political allies, they have a majority of seats in parliament.

The United States classifies Hezbollah as terrorist.

Hale, the US Under Secretary for Political Affairs, “will underscore America’s willingness to support any government that reflects the will of the people and is genuinely committed to and acting upon such a reform agenda”, the US Embassy said.

-AAP