A firefighter's helmet is seen near the epicenter of the blasts in Tianjin on Thursday morning. At least 17 firefighters were confirmed dead while more than a dozen were still missing by press time. Photo: Cui Meng/GT

Fires still burn on Thursday morning as fire trucks drive through hundreds of cars destroyed by the blasts. Photos: Cui Meng/GT

Citizens help carry a victim of the blasts into a hospital in Tianjin on Thursday. More than 700 were hospitalized and 50 people have died, according to local authorities. Photo: CFP

Graphics: AFP/GOOGLE EARTH/GT

The confirmed death toll in the deadly explosions that ripped through part of Tianjin's port area late Wednesday has risen to 50 by press time, with at least 701 people injured.

The fires, although under control, were still smoldering late Thursday, 24 hours after the explosions.

The two explosions, 30 seconds apart, rocked the Binhai New Area of eastern Tianjin at around 11:30 pm Wednesday, They sent blast waves kilometers from the area where a fire had first been reported at 10:50 pm in a warehouse storing hazardous and potentially toxic materials.

The cause of the initial blaze remains unknown, Zhang Yong, head of the Binhai district government said at a press conference in Binhai on Thursday.

The fire broke out at Tianjin Dongjiang Port Ruihai International Logistics, which is licensed to handle hazardous material. Executives from the company have been detained for questioning.

Seventeen firefighters have been confirmed dead, with more than a dozen missing and more than 60 hospitalized. Rescuers bore the brunt of the explosions, as they had rushed to the scene after the initial alarm was raised.

More than 1,000 firefighters from Tianjin and Beijing have been involved in the efforts to control the blaze. A team of 214 Beijing-based military specialists in handling nuclear and biochemical materials also arrived in Tianjin late Thursday to handle the hazardous materials. The warehouse was storing large quantities of the toxic chemical sodium cyanide, the Beijing News reported.

Tianjin Teda Hospital, the closest to the blast zone, was swamped with casualties on Thursday morning. Some 40 bodies were carried in, medical staff told the Global Times.

Many of the wounded had suffered burns, and also broken bones, cuts and bruises as the force of the explosions shattered windows and knocked people off their feet.

Many of the injured were later sent to other hospitals across the city.

Impact beyond description

The first explosion at 11:34 pm registered as a magnitude 2.3 earthquake, the second equal to a 2.9 - its power similar to the explosion of around 21 tons of TNT, said the China Earthquake Network Center Thursday. Japan's meteorological agency released pictures showing the blast from space.

The heat and shock waves left a large number of containers in ruins, charred hundreds of brand-new cars parked nearby, blasted through buildings and tore open windows and ceilings kilometers away, photos and videos uploaded by local people have shown.

Others showed shocked and dazed residents, some only dressed in their underwear, fleeing their homes in the aftermath of the blasts.

One injured local resident, surnamed Zhang, told the Global Times that when the blast wave reached his home, just 1 kilometer from the warehouse, it was so powerful that he was pushed from the window to another room.

"The ceiling was falling, and furniture was blown away," said another resident.

"The fire was like a mushroom cloud exploding to the sky and hard to describe; it was like a nuclear explosion," another witness told the Global Times.

3,500 relocated

Chinese President Xi Jinping and Premier Li Keqiang have urged all-out efforts in the search and rescue work to minimize casualties, said the Xinhua News Agency.

Xi said that the fire should be controlled and the cause of the disaster and the responsible party should be established as soon as possible. He stressed that the relatives of the dead and the injured should be supported and reassured.

Premier Li Keqiang also instructed the authorities to carry out a thorough and organized rescue. He also called for the timely and transparent disclosure of facts about the disaster.

A group of 1,500 People's Armed Police troops were dispatched to the site to support rescuers, reported the People's Liberation Army Daily.

Thousands of people have been left homeless. Some 3,500 residents were relocated to over 10 schools as temporary shelters. Water, food and medicines were provided, said Wang Jiancun, director of the Health and Family Planning Commission in Tianjin, at the press conference Thursday.

Daily necessities, including water and food, together with 800 folding beds and 1,600 towels have been sent to the relocation sites, said Wang.

Efforts to control the blaze were suspended at noon on Thursday as the quantity and nature of the dangerous materials and how they were stored were still being confirmed, reported China Central Television. Operations resumed later, with firefighters managing to take four fires under control. 

Hundreds of citizens in Tianjin lined up to donate blood, and the Beijing Red Cross Blood Center has said it also has enough supplies for emergency use.

The warehouse, located near the Tianjin Container Port, is 50 kilometers from downtown Tianjin, 165 kilometers away from downtown Beijing.