A powerful earthquake that flattened homes in Iran and Pakistan is believed to have killed 34 people and injured dozens more.
The 7.8 magnitude quake happened around 50 miles beneath the surface in a remote, mountainous region of southeast Iran, 115 miles from the city of Zahedan.
It is the most powerful to strike the country in 35 years and was felt across the Middle East.
However, Pakistan appeared to be worst affected, with a military official - speaking to AP on condition of anonymity - putting the death toll at 34.
At least 80 people were injured, he said.
Saleh Mangi, who was working in the Pakistani town of Thatta when the earthquake struck, said: "It was horrible. We felt the movement in the chairs and even the cupboards were shaking.
"This is the strongest quake I have felt since the 1980s."
Earlier, Iran's state-run Press TV said at least 40 people were killed on its side of the border.
However, Hatam Narouyi, governor of the country's Sistan and Baluchistan province, told news agency INSA there were "no fatalities".
The significant depth at which the earthquake occurred is the likely reason for the relatively low level of damage.
Morteza Moradipour, a spokesman for Iranian Red Crescent, said emergency crews, including dog teams, had been sent to the area to search for any buried survivors.
"Because of the strength of the earthquake we had expected to see significant damage in residential areas but the quake was at a depth of 95km and therefore the extent of the damage was on par with earthquakes measuring magnitude four," he said.
Strong tremors were felt across the Gulf, where high-rise buildings swayed and officials ordered evacuations.
The National newspaper said buildings were cleared in Sharjah, Abu Dhabi and Dubai, which is home to the world's tallest tower, the 828m Burj Khalifa.
The earthquake was also felt in New Delhi, where witnesses said tall buildings shook, sending people running into the streets.
Dr Brian Baptie, head of earthquake seismology at the British Geological Survey, said the earthquake happened in an area prone to tectonic activity.
He said: "This earthquake occurred in the great belt of earthquakes that stretches through the Middle East into central Asia that results from the collision of the northwards-moving Arabian and Indian tectonic plates with Eurasian tectonic plate to the north.
"Given the depth, the earthquake was probably a result of normal faulting within the Arabian plate as it is subducted under the Eurasian plate along the Makran coast of Iran and Pakistan."
The tremors came a week after a deadly 6.1 magnitude earthquake was recorded 60 miles southeast of Bushehr, the site of Iran's nuclear reactor.
On Boxing Day 2003, more than 26,000 people were killed when a 6.6 magnitude quake struck Bam.