DHAKA — A fire and a huge explosion have killed at least 34 people and injured hundreds more at a storage depot near the city of Chittagong, Bangladesh.

Hundreds of people had arrived to tackle the fire when a number of shipping containers exploded at the site in Sitakunda.

The cause of the fire is not known, but it is thought that chemicals were stored in some of the containers.

Hospitals in the area are overwhelmed and have appealed for blood donations.

Many of the injured are reported to be in a critical condition and the number of people killed is expected to rise.

"The explosion just threw me some 10 meters from where I was standing. My hands and legs are burned," lorry driver Tofael Ahmed told AFP news agency.

Volunteers, some wearing only sandals on their feet, continued to bring bodies from the smoldering wreckage on Sunday morning.

At least five firefighters were killed in the blast and several more were injured.

Several journalists who were reporting on the fire before the explosion are unaccounted for.

The blast was so large it was heard several kilometers away and shattered the windows of nearby buildings.

One local shopkeeper told reporters that a piece of debris had flown half a kilometer and landed in his pond. He described seeing "fireballs falling like rain" after the explosion.

Pictures of the aftermath show the twisted remains of metal shipping containers and the collapsed roof of a warehouse. A local journalist told the BBC that there was a pungent odor in the air.

Firefighters were still struggling to put out the fire on Sunday, with continued explosions making it more difficult, according to fire officials.

"We still could not control the fire because of the existence of this chemical," said Main Uddin, the head of the Bangladesh fire service.

The army has been deployed to prevent chemicals flowing into the sea.

Sitakunda is only 40km (25 miles) from Chittagong, and one of the city's hospitals has been inundated with victims. Military clinics are helping to treat the injured.

Around 4,000 containers were stored at the depot in Sitakunda, which is a transit point for containers traveling through the port in Chittagong — Bangladesh's second-largest city.

A regional government official said the depot contained millions of dollars of garments waiting to be exported to Western retailers.

Bangladesh is a major supplier of clothing to the West and has prospered over the past decade to become the world's second largest exporter of garments.

But lax regulations and poor enforcement of rules have often been blamed for industrial accidents, including several large fires that have led to hundreds of deaths in recent years.

Last year, at least 39 people were killed after a ferry caught fire in the south of the country. And earlier that same year, at least 52 people died in a factory fire in Rupganj near the capital, Dhaka.

Three workers were also killed in 2020 after an oil tank exploded in another container storage depot in Patenga, not far from Chittagong. — BBC