A burst pipe in Heathrow's Terminal 5 baggage hold Monday has left 100 bags soaked in raw sewage, The Independent reports.

The owners of the bags were forced to leave them behind as the airport sent them off to be cleaned, and some passengers are still waiting for their luggage to be returned.

The smell was absolutely foul, as was the mood of the passengers who had to leave without their bags,” one passenger told The Sun.

According to the paper, there are concerns that the problem stems from Terminal 5 having been built on a former sludge works.

“There was a leak from the sewage system in the baggage area of Terminal 5 on Monday which affected around a hundred bags," a spokesperson for airport operator BAA Heathrow is quoted as saying on ITV News. "We appreciate this will be upsetting for passengers. The bags have now been cleaned and are being reunited with their owners."

British Airways also issued an apology to its passengers for the inconvenience.