Lebanon's political and religious Sunni leaders threw their weight behind caretaker Prime Minister Hassan Diab on Friday, a day after he was charged with criminal negligence over the deadly explosion at Beirut port. Mr Diab was one of <a href="https://www.thenationalnews.com/world/mena/lebanese-prime-minister-and-three-former-ministers-charged-over-beirut-blast-1.1126267">four politicians indicted on Thursday</a> by a judge appointed to investigate the August 4 blast. All four were charged with carelessness and negligence leading to death over the detonation of 2,750 tonnes of ammonium nitrate stored at the port for six years. It is still unclear what caused the fire that set off the explosion or who owned the chemicals. The blast killed more than 200 people, injured about 6,500 and destroyed large areas of the capital. Prime minister-designate Saad Hariri expressed solidarity with Mr Diab, tweeting photos of the two leaders sitting side by side during a meeting at the prime minister's office on Friday, and accusing the judiciary of "violating the constitution". Both leaders said the indictment was an attack on the post of prime minister, a position reserved for Sunnis under Lebanon's unwritten sectarian power-sharing arrangement. "Lebanese families have the right to know the truth of who killed their sons," Mr Hariri said. Three former ministers charged alongside Mr Diab – Ali Hassan Khalil, Ghazi Zaeiter, and Youssef Fenianos – are expected to be brought in for questioning by the prosecution next week. Responding to the indictment, Mr Diab said his "conscience is clear", and he was confident his he "handled the Beirut explosion file in a responsible and transparent manner". Mr Diab, who came to power in January and stepped down soon after the explosion, has said he was informed about the ammonium nitrate at the port by state security services just two weeks before the explosion. Mr Diab also received the backing of Lebanon’s top Sunni religious leader, Mufti Abdul Latif Derian, who praised the caretaker prime minister and said he was confident the premier’s “hands were clean”. Former prime minister Najib Mikati also tweeted about the charges against Mr Diab, saying they showed a "double standard" because Lebanese President Michel Aoun was also aware of the report about the explosive material at the port but has not been investigated. Mr Mikati’s remarks were echoed by former another prime minister, Fouad Siniora, who said the charges were politically driven. The port blast exacerbated Lebanon's economic and political crisis. The EU, UN and World Bank estimate the the country needs $2.5 billion to recover from the blast, but Lebanese politicians are under pressure to institute reforms before the government receives any international assistance.