The Houses of Parliament, left, and the London Eye, right, on Thursday. (Lefteris Pitarakis/AP)

LONDON — No, that cityscape shrouded in smog is not Beijing. It’s London.

For the second day in a row, the British capital was blanketed Thursday  with dirty air, prompting a rise in emergency calls to London ambulance services from people reporting breathing difficulties.

The pea-soup air that is hanging over London and large swaths of Britain is a cocktail of home-grown pollutants, emissions from continental Europe and dust blown in from the Sahara Desert some 2,000 miles away. To make matters worse, there have been only very light winds.

Even British Prime Minister David Cameron admitted that the weather was “unpleasant,” adding that he had canceled his morning run.

Cameron was blasted by environmentalists for blaming the poor air quality only on dust from the Sahara.

“We know that the dust was a contributing factor,” said Keith Taylor, a Green Party Member of the European Parliament. “But the government also know that 80 deaths every day in the U.K. are caused by air pollution, and that we simply aren't doing enough to tackle the smog coming from our cars and factories,” he said in a statement.

As London’s air pollution levels reached 10 on a 10-point scale Thursday, health authorities urged people with underlying health issues to refrain from strenuous activity outdoors. Some schools in London banned children from playing outdoors during lunchtime.

Laura Young, a spokeswoman for the Met Office, Britain’s national weather service, said that Britain experiences similar levels of air pollution up to five times a year but that this case had caught the public’s attention in part because motorists are seeing a red-colored dust from the Sahara on their cars.

“It’s given people something they can see. They see their cars covered in thick dust and they say, ‘Okay, I'm quite worried about this because I can see it happening,’ ” Young said.

The thick haze is expected to begin clearing Friday with clean, cooler air blowing in from the Atlantic Ocean.