A violent, shallow earthquake having a preliminary magnitude of 7.8 has rocked a wide area of southeastern Iran near the Pakistan border.
At least 40 people were feared dead, according to Iranian state media, monitored by CNN.
The quake struck at 1044 UTC, or 6:44 a.m. EDT, in a desert region about 50 miles east of Khash, Iran, the USGS Earthquake Hazards website said. The preliminary focal depth was 15.2 km, or 9.4 miles, making it a very shallow shock.
The USGS PAGER page estimated that more than 340,000 people were subject to intensity VII shaking, which is described as "very strong," having "moderate" to "heavy" damage potential.
Strong to very strong shaking reached well into western Pakistan and even southwestern Afghanistan.
A poster to the USGS "Did You Feel It?" page reported feeling the quake in Karachi, Pakistan, nearly 400 miles from the preliminary epicenter.
Buildings shook "for 40 seconds or more" in Abu Dhabi, CNN reported.
The shaken area is desert, having rugged mountain ranges and broad valleys.