Pakistan’s prime minister called for emergency measures as the death toll from a heatwave in southern Sindh province topped 450.

Pakistan's prime minister called for emergency measures as the death toll from a heatwave in southern Sindh province topped 450.

The National Disaster Management Authority (NDMA) said it had received orders from Nawaz Sharif to undertake immediate response measures.

The army has also been deployed to set up heat stroke centers and assist the NDMA, it added.

Many of the victims are elderly people from low income families.

Health officials say many deaths have been in the largest city, Karachi, which has experienced temperatures as high as 45C (113F) in recent days.

Hundreds of patients suffering from the effects of the heatwave are being treated at government hospitals, provincial health secretary Saeed Mangnejo said.

The demand for electricity for air conditioning has coincided with increased power needs over Ramadan, when Muslims fast during daylight hours.

Hot weather is not unusual during summer months in Pakistan, but prolonged power outages seem to have made matters worse, the BBC reported.

Sporadic angry protests have taken place in parts of the city, with some people blaming the government and the city's main power utility, K-Electric, for failing to avoid deaths, the BBC added.