Firefighters put out a blaze after an explosion ripped through a roadside warehouse for shoe-making materials in Guangzhou on Tuesday, killing at least four and injuring 36. Thirteen children from a nearby kindergarten were among the injured. Zhou Wei / for China Daily

An explosion in a storehouse for shoe-making materials in Guangzhou on Tuesday killed at least four people and injured 36, the city said on its micro blog.

At least 13 children at a nearby kindergarten were injured by flying glass from windows smashed by the shock wave.

The blast took place at 11:50 am in a storehouse opposite the Ezhangtan archway in Baiyun district, according to a witness named Chen Xiaohong who works in a ventilator shop across the road from the storehouse.

"It was as terrifying as an earthquake. The glass of our shop door was broken and the ventilators on the shelf fell off. I was frozen for a few seconds before I rushed out of the shop," Chen said.

Chen Liting lives on the fourth floor of the building next to the shop. "Luckily, I was on the way home from school when the explosion happened. My mother told me she saw flames three or four meters high," the college freshman said.

The city's fire department sent 17 fire engines and three command cars to the scene. At 1:50 pm, the department announced on its micro blog that the fire had been extinguished.

However, smoke was still pouring out of the storehouse when a China Daily reporter left the scene at 5 pm. The choking smoke was still affecting people 1 kilometer away.

Preliminary investigations suggest that the explosion was caused by a truck unloading dangerous cargo.

The environmental protection bureau announced that there were no toxic fumes at the site by 7:20 pm.

Netizens posted pictures on Sina Weibo showing damage caused by the blast.

Standing on a nearby rooftop, witnesses were able to see an entire corner of the storehouse had been removed in the blast.

Guangzhou's Xinshi Hospital received 13 injured children from the kindergarten, five of whom had been hospitalized as of press time. Most of the children, aged from 2 and a half to 5 years old, had skin lacerations, said Lu Anping, director of the hospital's medical department.

"Besides surgeons, we also assigned pediatricians to offer counseling to calm down the frightened and crying children, and plastic surgeons to help reduce the risk of facial scars," Lu added.

Wan Qingliang, Party chief of Guangzhou, visited the injured children in Xinshi Hospital and offered his support.

Huang Yiqing, 5, one of the injured children, said she was lying on her bed when she heard loud explosions that she said sounded "like firecrackers".

"The window smashed. I climbed down from my bed and my teacher grabbed me and we rushed out of the room," recalled Huang, the top of her T-shirt stained with blood.

"I didn't feel any pain at that time, but now the wounds hurt," she said.

A 3-year-old girl with a deep wound on her knee who was sitting on the bed next to Huang cried continually.

"I ran to the kindergarten when I heard the explosion and I was shocked when I saw blood all over her chest and feet," said the mother, Lin Tao, who couldn't hold back her tears.

"My daughter would hide under the quilt when she heard firecrackers during Spring Festival. So I can imagine how scared she was. I hope the fear in the accident won't haunt my daughter."