More than 500 people are believed to have died in a heatwave in India as temperatures approach 50C (122F) in parts of the country.

Allahabad, a city in the north, saw the mercury touch 47.7 C (117.8F) on Sunday, according to local media. In Delhi, the capital, a high of 43.5C (110.3F) was recorded.

Most of the recorded deaths, primarily from heatstroke and extreme dehydration, have been in rural areas in the south, where roads and markets were deserted in many cities and towns. Local authorities announced a compensation payment of £1,000 to relatives of those killed.

The forecast is for a continuing “heatwave to severe heatwave” for the rest of the month. “It is hot. It will stay hot. People must stay inside and drink lots of water,” Devendra Sharma, an official at the Indian meteorological office said.

In the city of Kolkata, in the east, taxi drivers refused to work between 11am and 4pm after a driver died in his cab.

Across the country, there were power cuts as India’s inadequate electricity networks sought to fulfil record demand. Shopping malls, which are air-conditioned and often have their own generators to keep customers cool during frequent outages, recorded a surge in visitors.

“We see more and more people walk in, spend some time here and walk out without buying anything. But we understand. It’s terribly hot outside,” Nasir, a security guard at a mall in the city of Patna, told the Times of India newspaper.

In Delhi, where temperatures were four degrees higher than the seasonal average, many sought sanctuary in the air-conditioned metro. The highest temperature ever recorded in the capital was 47.2C (116.9F), in May 1944. The record India is thought to be 50.6C (123F), recorded in 1956 in the northern town of Alwar (pdf).

The death toll is worse than the severe heatwave in 2010, which started much earlier, registered the highest temperatures for decades and lasted for months.

The monsoon, predicted to hit southern India’s coastline on 31 May, will bring relief from the high temperatures, but it will not reach the parched north of the country for several weeks.