The Prince of Wales and Duchess of Cornwall battled through thick smog on Wednesday as they landed for their official visit to New Delhi to find a public health emergency and all schools closed.

The Prince and Duchess landed in New Delhi from Malaysia on Wednesday, on the last leg of their Commonwealth tour, to be greeted by pollution nearly 30 times the World Health Organisation’s safe level.

Despite the conditions, which saw a thick white smog shroud their aeroplane as it landed, they appeared determined to continue with their planned programme, spending time at a charity garden party outdoors.

While the Royal couple persevered with their engagements, members of the public were seen wearing masks and covering their mouths with handkerchiefs and scarves as they walked at the side of the roads.

By Wednesday afternoon, the concentration of PM 2.5 - the microscopic particles that are the most damaging to health -had risen to 999 in some areas: reported to be the maximum which can be measured on the city’s equipment.

The US Embassy, the nearest measurement to where the Prince and Duchess are staying, showed a measurement of 316, classed as "hazardous".