People of London reported about a mysterious odor, described as "acrid, noxious," most likely a “chemical smell" across parts of city Wednesday night. The smell appeared to be affecting areas stretching from Victoria to Wapping in east London as well as areas in the south-east such as Bermondsey, Rotherhithe and Camberwell.

Panic struck among Londoners as some described the smell as "Dettol meets battery acid." Lana Preston, 51, of Bermondsey, told the BBC she was worried it might be "something hazardous or poisonous."

"It's like a very strong smell - like a sweet rubber smell. I've never smelt anything like it," she said, adding the smell could be linked to a foggy haze over London.

The London Fire Brigade (LFB), the Health and Safety Executive, and the Environment Agency said they had no reports of a smell, according to BBC. A spokeswoman said the LFB could not investigate unless people call 999.

However, social media flooded with people complaining of the smell, with some saying they were facing breathing difficulties due to the odor.

One Twitter user said the air in the capital smelled "like chlorine" while another one described it as "noxious."

Anastasia Yankevich tweeted there was an "odd smell lingering around London all day," while another wrote: "The air in central London stinks."

Dr. Thomas Smith of London School of Economics (LSE) claimed the stench in London could be down to the high levels of air pollution in the city.

"The air quality in London right now is 'unhealthy.' It's so bad that you can smell it. AQI 102 is the highest we've recorded @LSEGeographysince we began measuring in May," he wrote.​