ISLAMABAD - A powerful earthquake of magnitude 7.2 shook southwestern Pakistan early on Wednesday, jolting residents of cities as far apart as Delhi and Dubai, but the epicentre was far from major population centres.

The U.S. Geological Survey said the quake was more than 80 km (50 miles) underground, close to the town of Dalbandin in Baluchistan province, near the Afghan and Iranian frontiers.

Poor communications ensured there were few immediate reports from the vicinity of the quake, but despite the major strength of the shock, the great depth may have limited damage. The USGS had first said that the earthquake was very much shallower.

The USGS said the epicentre was 55 km (34 miles) west of Dalbandin, a town of about 15,000 people, and at a depth of 83 km (52 miles).

In Dalbandin, several people were injured when the roofs of their houses collapsed, provincial Transport Minister Amanullah Notizai told Reuters, but so far there were no reports of fatalities in the quake which hit at 1:23 a.m. (2023 GMT on Tuesday).

People in India's border province of Rajasthan said cracks appeared in the walls of rural dwellings.

U.S. forces across the border in Afghanistan were unaffected by the quake, according to preliminary reports from the U.S. military.

As dawn breaks and officials reach the affected area, more damage and fatalities may be revealed in an area where traditional simple structures may have fared badly under the strains of the powerful tremor.

People flee their houses

In Quetta, the largest city in Baluchistan and 331 km (205.7 miles) northeast of the epicentre, a woman died at a city hospital from a heart attack following the quake, hospital officials said.

And in the major Pakistani port of Karachi, 400 km (250 miles) away, people woke and rushed from their homes after the tremors. An official at Edhi Foundation, the biggest private ambulance and rescue service in Karachi, said there were no reports of any damage.

"I was sleeping when the quake struck and I felt like my bed was shaking. I got up and ran to check the children...and thankfully they were all okay," said Masooma Rizvi, a housewife. "It was very scary. I have never felt anything like this before."

The Pacific Tsunami Center said the onshore quake had not triggered a tsunami in the Indian Ocean.

A major quake of this magnitude, if at a shallow depth and close to population centres, is capable of causing widespread and heavy damage. Pakistan is still reeling from devastating floods last year that left more than 10 million people homeless.

In 2005, a 7.6 magnitude quake 95 km (60 miles) northeast of the Pakistani capital Islamabad killed over 70,000 people.