More than 160 people were killed in Iraq and Iran on Sunday when a powerful magnitude 7.3 earthquake hit the region, state media in the two countries said, as rescuers searched for dozens trapped under rubble.
At least 164 people were killed in Iran, Behnam Saeedi, a spokesman for Iran's National Disaster Management Organization said on state television. More than 1,650 were injured, he said.
Officials expected the casualty toll to rise when search and rescue teams reached remote areas of Iran.
A quake registering a magnitude between 7 and 7.9 can inflict widespread and heavy damage. Moreover, many houses in rural areas of Iran are made of mud bricks that can crumble easily in a quake.
The earthquake was felt in several provinces of Iran but the hardest hit province was Kermanshah, which announced three days of mourning.
More than 97 of the victims were in Sarpol-e Zahab county in Kermanshah, about 15 km (10 miles) from the Iraq border.
The main hospital of the capital of the county was severely damaged and could not treat hundreds of injured people who were taken there, the head of the Iranian emergency services, Pirhossein Koulivand said.
The US Geological Survey said the quake measured magnitude 7.3. An Iraqi meteorology official put its magnitude at 6.5 with the epicentre in Penjwin in Sulaimaniyah province in the Kurdistan region close to the main border crossing with Iran.
Kurdish health officials said at least four people were killed in Iraq and at least 50 injured.
The quake was felt as far south as Baghdad, where many residents rushed from their houses and tall buildings when tremors shook the Iraqi capital.