"It does not end with the government's resignation," said the protest flyer circulating on social media. "There is still (President Michel) Aoun, (Parliament Speaker Nabih) Berri and the entire system."
For many Lebanese, the explosion was the last straw in a protracted crisis over the collapse of the economy, corruption, waste and dysfunctional government.
Sectarian system
The Beirut port mirrors the sectarian power system in which the same politicians have dominated the country since the 1975-90 civil war.
Each faction has its quota of directors at the port, the nation's main trade artery.
"It's a good thing that the government resigned. But we need new blood or it won’t work," silversmith Avedis Anserlian told Reuters in front of his demolished shop.
Diab formed his government in January with the backing of the powerful Iranian-backed Hezbollah group and its allies.
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It came more than two months after Saad Hariri, who had enjoyed the backing of the West and Gulf states, quit as premier amid anti-government protests against corruption and mismanagement.
Aoun is required to consult with parliamentary blocs on who should be the next prime minister, and is obliged to designate the candidate with the most support.