A fire and a huge explosion have killed at least 49 people and injured hundreds more at at a shipping container depot near the city of Chittagong in Bangladesh, officials said on Sunday.

The toll was expected to rise, with some of the more than 300 people injured in serious condition, officials said, while volunteers reported that there were more bodies inside the smouldering, wreckage-strewn facility.

The fire started late on Saturday at the depot in Sitakunda, which stores around 4,000 containers, many of them filled with garments destined for Western retailers. The facility is about 40 kilometres (25 miles) from the major southern port of Chittagong.

Following the fire, containers holding chemicals exploded, engulfing firefighters, volunteers and journalists in an inferno, hurtling people and debris through the air, and turning the night sky a blazing orange.

Buildings located kilometres away rattled with the force of the blast.

Hundreds of people had arrived to tackle the fire when a number of shipping containers exploded at the site in Sitakunda. It is thought that chemicals were stored in some of the containers.

Industrial fires are common in Bangladesh, and are often blamed on poor safety regulations.

Many of the injured are said to be in a critical condition and the number of people killed is expected to rise. Hospitals in the area are overwhelmed and have appealed for blood donations.

The fire broke out at around 21:00 local time (15:00 GMT) on Saturday and hundreds of firefighters, police and volunteers quickly arrived on the scene.

As they tried to extinguish the blaze a huge explosion rocked the site, engulfing many of the rescuers in flames and throwing debris and people into the air.

“The explosion just threw me some 10 metres from where I was standing. My hands and legs are burnt”,  lorry driver Tofael Ahmed told AFP news agency.

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

At least five firefighters were killed in the blast and several more were injured. Many people are still missing, including several journalists who were reporting on the fire before the explosion.

The blast was so large it was heard several kilometres away and shattered the windows of nearby buildings. One local shopkeeper told reporters that a piece of debris had flown half a kilometre and landed in his pond. He described seeing “fireballs falling like rain” after the explosion.

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 goods travelling through Chittagong – Bangladesh’s main sea port and second-largest city.

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

Many people in Bangladesh are comparing the explosion to the huge blast that hit Beirut in 2020, says the BBC’s Akbar Hossain in the capital, Dhaka. He says people have reported hearing the blast from 30-40km (19-25 miles) away.

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 odour in the air.

Elias Chowdhury, regional chief doctor, told AFP that the number of dead was 49 but would increase. Firefighters continued to douse pockets of fire with hoses on Sunday.

“The death toll will rise as the rescue work has not been completed yet. These people including several journalists who were doing Facebook lives are still not accounted for”, Chowdhury said.

Reazul Karim, operations director of the fire department, said that at least seven firefighters died and that at least four others were missing.

“Never in our fire department history have we lost so many firefighters in a single incident There are still some bodies inside the fire-affected places. I saw eight or 10 bodies”,  one volunteer told reporters.

Mujibur Rahman, the director of B.M. Container Depot, the firm operating the facility with around 600 workers, said that the cause of the initial fire was still unknown.

The container depot held hydrogen peroxide, fire service chief Brigadier General Main Uddin told reporters.

“We still could not control the fire because of the existence of this chemical”,  he said.

“Fireballs falling like rain. The blast was deafening. A cylinder flew around half a kilometre from the fire spot to our small pond when the explosion occurred. The explosion sent fireballs into the sky. Fireballs were falling like rain. We were so afraid we immediately left our home to find refuge… We thought the fire would spread to our locality as it is very densely populated”, said Mohammad Ali, 60, who runs a nearby grocery store.

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 safety regulations are often ignored or poorly enforced, and there have been several large fires and other incidents at factories in recent years.

On Sunday, the Dhaka Tribune newspaper published a list of 12 industrial disasters – including fires, building collapses and chemical leaks – that have killed over 1,000 people since 2005.