CHITTAGONG, Bangladesh - At least five people were killed and dozens injured in an explosion at an oxygen plant outside Bangladesh’s port city of Chittagong on Saturday, officials said.

The blast rocked the oxygen unit of the Sheema steel re-rolling mill in the industrial town of Sitakunda, 40km from Chittagong.

The incident occurred at around 4.30pm local time, trapping “many workers” inside the plant, local police chief Tofael Ahmed said.

“The fire brigade has doused the fire and they rescued the people from the plant,” he added.

District administrator Mohammad Fakhruzzaman told AFP at least five people were killed in the explosion and another 25 people were injured.

Officials said the death toll could rise as a rescue operation was ongoing.

Witness Muslim Uddin said the explosion was “so loud and devastating” that it shook all residential houses in the area.

“Glass in many houses was shattered. The entire area went dark,” he told AFP.

The government has ordered a probe into the explosion.

Industrial explosions and fires are common in Bangladesh where safety enforcement by the factory authorities is poor.

In June last year, a fire and subsequent explosions at a container depot in the same industrial town left more than 50 people dead. AFP, REUTERS