At least 19 people have been killed and 140 injured in an explosion inside an office building in the Bangladeshi capital Dhaka, police and fire service officials have said.

According to international media reports, the explosion shook the fourth and fifth floors of a five-storey building in Gulistan, a major hub for wholesale goods in the capital, shortly before 5pm local time (11:00 GMT) on Tuesday.

Authorities could not immediately provide the reason behind the huge explosion in the bustling commercial area.

“At least 19 people have died, including two women,” police inspector Bacchu Mia told reporters.

Mia said more than 140 had been brought to the Dhaka Medical College Hospital (DMCH).

More than 112 people were treated for head wounds, fractures and other injuries at DMCH, hospital director Nazmul Islam told newsmen.

“The pattern of the injuries shows that it was a huge explosion,” he said, adding that hundreds of doctors and nurses were mobilised.

He said some injured people were also sent to other hospitals in the city.

No fire broke out in the building but more than 150 firefighters were at the site to assist in rescue efforts, a fire services spokesperson said.

A middle-aged man in a blood-soaked shirt told reporters he had been injured in the blast, which shattered windows and damaged a wall of the building.

“There were people lying on the floor. I escaped by climbing out from the window,” he said.

Even though rescuers got to the scene within seven minutes of the blast, the extent of the damage has hampered their efforts to reach people who may still be stuck inside, according to Fire Department Chief Brigadier General Main Uddin.

“It’s risky to enter the building now,” he said. “We needed reinforcements for columns and beams to continue rescue (efforts) on the ground floor and the underground,” Uddin said.

“There is still the possibility of people stuck inside the building,” he said.

He added that there was no gas line under the building and no sign of explosives.

“We are trying to find the reason (for the blast),” he said.

Bangladesh has a history of industrial disasters, including factories catching fire with workers trapped inside. Monitoring groups have blamed corruption and lax enforcement.

In 2012, about 117 workers died when they were trapped behind locked exits in a garment factory in Dhaka.

The country’s worst industrial disaster occurred the following year, when the Rana Plaza garment factory outside Dhaka collapsed, killing more than 1,100 people.

In 2019, a blaze ripped through a 400-year-old area cramped with apartments, shops and warehouses in the oldest part of Dhaka and killed at least 67 people. Another fire in Old Dhaka in a house illegally storing chemicals killed at least 123 people in 2010.

In 2021, a fire at a food and beverage factory outside Dhaka killed at least 52 people, many of whom were trapped inside by an illegally locked door.

Last year, a fire at a shipping container storage depot near the country’s main Chittagong Seaport killed at least 41 people, including nine firefighters, and injured more than 100 others.