One of the strongest earthquakes to hit Iran in 50 years has flattened homes and offices on both sides of its border with Pakistan, killing at least 46 people in the sparsely populated region and shaking buildings as far away as New Delhi.
Iran's Red Crescent said it was facing a "complicated emergency situation" in the area with villages scattered over desolate hills and valleys.
It measured at least magnitude 7.7, as the strongest quake in more than 50 years. It also was the second deadly quake to hit Iran in less than a week after a magnitude 6.1 tremor struck near Bushehr, on Iran's Persian Gulf coast, killing at least 37 people and raising calls for greater international safety inspectors at Iran's lone nuclear reactor nearby.
The latest quake was centred near Saravan, about 26 miles from the Pakistani border.
Iran's state TV said least 40 people were killed, but gave no other details on the extent of damage or casualties. State-run Pakistan Television, meanwhile, said at least six people were killed on its side of the border and at least 47 others were injured. Up to 1,000 mud homes were damaged.
The quake was felt over a vast area from New Delhi to Gulf cities that have some of the world's tallest skyscrapers, including the record 2,717 -foot Burj Khalifa in Dubai. Officials ordered temporary evacuations from some high-rises as a precaution.
In the southern Pakistani city of Karachi people in panic came out from offices and homes.
In 2003, 26,000 people were killed by a magnitude 6.6 quake that flattened the historic south-eastern Iranian city of Bam.