An image grab obtained from Lebanon's public television network Tele Liban on Aug 10, 2020 shows Prime Minister Hassan Diab announcing his government's resignation amid popular outrage over the deadly Beirut port explosion. (TELE LIBAN / AFP)

BEIRUT- Lebanon’s investigating judge has charged caretaker Prime Minister Hassan Diab and three former ministers with negligence over the Beirut port blast that killed 200 people and ruined a swathe of the capital in August.

The others are former finance minister Ali Hassan Khalil, as well as former public works ministers Ghazi Zeaiter and Youssef Finianos, state news agency NNA said on Thursday.

Diab said on Thursday his conscience was clear over the Aug 4 Beirut port blast after the judge investigating the explosion charged him with negligence

ALSO READ: Beirut bent on restoring heritage buildings damaged in blasts

Zeaiter headed the public works and transport ministry in 2014, shortly after the arrival of the Rhosus ship carrying a huge stockpile of ammonium nitrate which detonated at the port.

Officials have said the cargo of ammonium nitrate, a highly explosive chemical, was stored unsafely for years at the port, which lies in heart of the city.

READ MORE: FBI says it has reached no conclusion on cause of Beirut blast

Diab said on Thursday his conscience was clear over the Aug 4 Beirut port blast after the judge investigating the explosion charged him with negligence.

Diab said in a statement he was confident that his hands were clean and that he had dealt transparently with the file of the Beirut port explosion, adding that he was surprised to be targeted by the investigating judge.

Four months after one of the largest non-nuclear explosions on record, which injured thousands of people, victims are still waiting for the results of an investigation their leaders had promised would come within days of the Aug. 4 port blast.

The judge leading the official inquiry, Fadi Sawan, sent a letter last month asking parliament to probe 10 former ministers.