A Biman Bangladesh Airlines flight bound for Abu Dhabi has turned back mid-air after its lavatory system reportedly stopped functioning, forcing all passengers to return to Dhaka after nearly an hour into the journey.

Passengers said they faced long delays and considerable discomfort before they were eventually flown out on a replacement aircraft.

Flight BG-0327 was scheduled to depart from Dhaka’s Hazrat Shahjalal International Airport at 9:55pm on Thursday and land in Abu Dhabi at 1:55am local time.

One of the passengers, Mohammad Mosharraf Hossain, a resident of Fatikchhari in Chattogram and an expatriate in Abu Dhabi, told bdnews24.com that passengers were initially informed that the flight would take off around 10:45pm, but it did not depart until midnight.

“About an hour after takeoff, the crew announced that none of the three lavatories were working. The captain was returning the flight to Dhaka,” he added.

According to Mosharraf, after landing back in Dhaka, the passengers were taken by bus to another aircraft. They were kept waiting inside the bus for a prolonged period before boarding, with the air conditioning turned off -- prompting frustration among many.

The replacement flight eventually departed for Abu Dhabi at around 3:15am Bangladesh time, he said.

Shahadat Hossain, Biman’s regional director for Abu Dhabi and Al Ain, confirmed the flight disruption.

He said necessary services were provided to passengers during the delay.

On the same day, another Biman flight from Sylhet to London was diverted to Istanbul after a passenger fell ill mid-air.