Lebanon’s government is reportedly placing an unspecified number of Beirut port officials under house arrest pending an investigation into Tuesday's explosion.

The blast that rocked the country's capital has so far claimed the lives of 135 people and injured more than 5,000.

President Michel Aoun said the explosion was caused by 2,750 tonnes of ammonium nitrate stored unsafely in a warehouse within the port zone.

Lebanon's Supreme Defence Council has vowed to give the "maximum punishment" possible to those found responsible by what it promises will be a full and transparent investigation.

Information minister Manal Abdel Samad said the house arrests would apply for all port officials "who have handled the affairs of storing [the] ammonium nitrate, guarding it and handling its paperwork" since June 2014, according to the BBC.

Raoul Nehme, the country’s economy minister blamed incompetence and bad management on the part of port authorities and previous governments during an interview with the BBC.

The ammonium nitrate that has been fingered as the cause of the blast arrived at the Lebanese capital in 2013 on the Moldovan-flagged general cargoship Rhosus (built 1986). The 3,226-dwt ship was, en route to Mozambique, diverted to Beirut due to mechanical issues.

The vessel was subsequently detained by port authorities over deficiencies and later abandoned by its owner.

The Rhosus and its dangerous cargo were seized. The ship was later sold, and a judge ordered the cargo be “taken to an appropriate location for a guarded storage," according to court documents obtained by CNN.

The head of Beirut's port and the head of the customs authority have both claimed that they had written to the judiciary several times asking that the chemical be exported or sold on to ensure port safety, but the legal officials never responded.

The director of Lebanese Customs, Badri Daher, said his agency repeatedly called for the chemical to be removed, but "this did not happen".

Public documents showed Daher and his predecessor, Chafic Merhi, requested the dangerous cargo be removed from the port in 2014, 2015, 2016 and 2017, CNN confirmed on Thursday.

The port’s general manager, Hassan Koraytem, told local news channel OTV that the port authority had been aware that the material was dangerous when the court first ordered it stored in the warehouse, "but not to this degree".

Total devastation

The Beirut explosion, which specialists at the University of Sheffield have described as "unquestionably one of the biggest non-nuclear explosions in history", has decimated the city and its port.

Global port agency network Gulf Agency Co said the explosion "destroyed almost everything in the port and the surrounding area up to a radius of 10 km".

It is estimated up to 300,000 people have been made homeless with between $3bn and $5bn worth of damage done to the city.

Hundreds more people are still missing.

Satellite images following the blast showed two small coastal cargo ships that were docked in close proximity to the warehouse thrown onto the dock a fair distance away.

Another small general cargo ship tied up directly alongside the warehouse is reported to have “simply vanished”.

Abou Merhi Cruises’ 7,500-gt cruiseship Orient Queen (built 1989), moored at a pier opposite the blast epicenter, was body-slammed against the pier, ruptured its hull, and subsequently capsized. At least two crew members on the ship were killed and several more were injured.

TradeWinds has been unable to contact Abou Merhi Cruises for comment. Its offices are located close to the port.

A CMA CGM containership that was docked further away survived the blast unscathed, the French liner giant said on Wednesday.

CMA CGM said it had offered the Lebanese and French governments logistics and maritime assistance in order to respond to the emergency.

Tripoli, Lebanon's second-largest port, has been designated to take over cargoes that would have otherwise been handled in Beirut.

Minister of public works Michel Najjar said on Wednesday that the country's government was assessing Tripoli's capabilities and those of other ports.

It is unclear how long Beirut’s port will remain closed.