A severe heat wave has killed hundreds here in Pakistan’s largest city, creating a public health emergency that has been exacerbated by a shortage of electricity and the Muslim holy month of Ramadan.

Health officials in Karachi estimate that more than 600 people have died of heatstroke and related illnesses in Sindh province, the vast majority of them in Karachi.

With temperatures soaring past 100 degrees since late last week, hospitals in the city were at capacity Tuesday as officials struggled to open temporary health clinics and cooling centers. Thousands of people have been pouring into hospitals seeking treatment. Some said their relatives died in sweltering cars as they drove for hours in search of medical attention.

On Monday afternoon, mortuary operators in the city announced that they had run out of freezer space for corpses. They pleaded with victims’ families to retrieve the bodies quickly so they could be buried.

Heat waves are common in Pakistan, but the past few days have been especially brutal. The temperature in Karachi reached 113 on Saturday, making it the hottest day in the city in at least 10 years, according to Pakistan’s meteorological service. High temperatures nearing 110 were also reported each of the following three days.

The heat has greatly strained Pakistan’s already sluggish electrical grid, resulting in widespread outages. On Tuesday, some Karachi residents said they had been without power for two days. This sparked protests against the government and the city’s main energy supplier, the private company K-Electric, which is majority owned by a Dubai-based private-equity firm.

The heat wave coincided with the start of Ramadan, when many Muslims fast between sunrise and sunset. Some Muslims, particularly in conservative countries such as Pakistan, refrain not only from eating while they fast but also from drinking water.

Doctors have been pleading with residents, particularly the elderly, to consider breaking their fast by at least drinking water to avoid dehydration.

Last month, a heat wave in neighboring India killed nearly 2,000 people.

In Pakistan, the crisis has threatened to undermine two of the country’s largest political parties. Karachi residents have accused Prime Minister Nawaz Sharif of failing to live up to a promise made this month that power cuts would be limited during Ramadan.

However, Sindh remains a stronghold of the Pakistan Peoples Party, while Sharif’s Pakistan Muslim League-N party is in the opposition in the provincial assembly. Although officials rushed to open cooling centers and water stations on Monday, residents said the measures should have been set into motion earlier.

With angry residents wandering the streets looking for a place to cool off, one police official told the Associated Press on Tuesday that some neighborhoods were sliding toward an “anarchy-like situation.”

“The situation in Karachi is one of chaos and lawlessness with no visible writ of the government,” Imran Khan, leader of the Movement for Justice party, said. “The people of Karachi have been effectively abandoned by the provincial and federal governments, both of whom have failed to provide the basic necessities of life.”

Craig reported from Islamabad, Pakistan.

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