Updated at 2 p.m. ET

An intense heatwave in Pakistan has now killed more than 600 people, the government said on Tuesday. Earlier, officials had put the death toll at more than 450.

NPR's Philip Reeves filed this report for our Newscast unit:

"So many people have died over the last three days that morgues in the city are struggling to cope. Karachi's always hot in the summer, but this year has seen temperatures of more than 111 Fahrenheit."The extreme heat's coincided with prolonged power outages. That, coupled with the city's inadequate health system, is leading to fierce criticism of the authorities."This is happening in Islam's holy month of Ramadan when most Muslims fast. Paramilitary forces are running makeshift medical camps on the streets to help people suffering from the heat. Officials say the victims include many elderly, suffering from fever and dehydration."

The BBC reports that in Karachi, Pakistan's largest city, hasn't seen this kind of heat in more than a decade.

The BBC adds:

"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."

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