IBTimes UK

At least 200 people required medical treatment after an explosion at a chemical fertiliser factory in Chittagong, Bangladesh late on Monday, spreading toxic gas across large parts of the city.

The police and fire officials said hundreds of residents were also evacuated from their homes near the di-ammonia phosphate (DAP) plant in Chittagong. Firefighters battled throughout the night to halt the leak of the 500-tonne capacity ammonia tank.

The authorities declared that the situation was under control in the mid-morning.

Mesbah Uddin, the district's chief administrator, said almost 56 people had been admitted the Chittagong Medical College Hospital after the gas leak. But none of them were in life-threatening conditions.

"Eight have been discharged. Forty-eight people are still in the hospital today but they are out of danger. Around 150 people were given first aid locally," Uddin told AFP.

"We used loudspeakers to urge people to evacuate the area. Hundreds did leave but they came back after the situation improved," he added.

Rafiqul Islam, the local police chief, confirmed that they have also ordered the workers working in nearby factories to leave their premises.

Officials said strong winds blew the toxic gas across a 10-kilometre radius and there were reports of people being taken ill at the southern city's international airport.

"We saved two other tanks by spraying water," Abul Kalam Azad, a senior fire official said. He added that the explosion took place while a tank was being refilled with ammonia gas.

Uddin said the government has ordered to investigate into the explosion. A three-member inquiry team was scheduled to visit the fertiliser plant onTuesday.