Update at 4:46 p.m. ET: The USGS has lowered the magnitude to 7.2 from 7.4 and said the quake occurred 50 miles deep, far deeper than the preliminary depth of six miles. It was centered in Baluchistan province, Pakistan's most sparsely populated.

Still no reports of damage or casualties.

The Associated Press reports that tremors lasting at least 20 seconds were felt as far away as Dubai, in the United Arab Emirates, and in India's capital, New Delhi.

Original post: A magnitude-7.4 earthquake has struck southwestern Pakistan near the Afghan border, the U.S. Geological Survey says.

No reports yet about casualties or damage.

The quake hit at 1:23 a.m. Wednesday local time, about 640 miles west of Islamabad, the capital.