Video shot from a drone today showed thick plumes of smoke rising over the charred remains of buildings and debris at the blast site in the Chinese port of Tianjin.
The explosions, which erupted late on Tuesday centred on a warehouse where volatile chemicals were stored in the northeast Chinese city and killed at least 56 people.
21 firefighters were among those killed, officials said. More than 700 people were injured, almost 60 seriously.
Gong Jiansheng, the deputy head of Tianjin's publicity bureau gave the latest figures out at a news conference.
"56 people have died, of which 21 were fire fighters, the total number in hospital is 721, of which 25 are in a critical condition and 33 are seriously injured," he said.
The columns of smoke from fires burnt amid the devastation of crumpled shipping containers, thousands of torched cars and port buildings reduced to burnt-out shells.
Rescuers pulled one survivor from the wreckage, a city official told reporters. State television later said it was a fire fighter.
The warehouse, designed to house dangerous and toxic chemicals, was storing mainly ammonium nitrate, potassium nitrate and calcium carbide at the time of the blasts, according to police.
The official Xinhua news agency has said several containers in the warehouse caught fire before the explosions.
Thousands of residents face another night sleeping in tents and school buildings, as a huge clean up operation is ongoing in the many housing complexes located just a few kilometres from the blast.
Zhang Ruigang, who heads the Binhai Municipal affairs office said over 6,000 residents had to be relocated.
"At present more than 6,300 residents have been relocated. At the same time we have been dispensing drinking water, food, and necessities such as clothes and bedding etc. At every temporary residence we have set up temporary medical services," he said.
Investigators continued to search for clues today to identify what caused the two huge explosions at a warehouse used to store toxic chemicals and gas at a busy port in northeast China, as foreign and local companies assessed the damage to their operations.