Pakistani troops in rescue effort after Iran quake
Pakistan has sent troops to help its citizens affected by a powerful earthquake that struck just over the border in south-east Iran.
The 7.8-magnitude quake, the most powerful to hit Iran for more than 50 years, caused 35 deaths in Pakistan's Balochistan province.
The National Disaster Management Authority say a further 150 people there have been injured.
The quake shook tall buildings as far away as India and the Gulf States.
It struck in the Iranian province of Sistan Baluchistan at about 15:14 local time (10:44 GMT) on Tuesday close to the city of Khash, which has a population of nearly 180,000, and Saravan, where 250,000 people live.
Its depth was about 95km (59 miles).
The area most affected on the Pakistani side is a remote location close to the Iran border called Mashkel. Getting there from the provincial capital Quetta can take 10-12 hours.
Travelling by road in Balochistan is considered very risky because of frequent attacks and kidnappings blamed on separatist insurgents and extremist Sunni groups.
Baloch nationalists in turn accuse the Pakistani army of widespread abuses and keeping the province effectively under army occupation, with tens and thousands of paramilitary troops deployed across the country's largest province.
Since Tuesday, the army has sprung into action to fly helicopters to deliver medicines, rations and tents to the earthquake survivors. Many believe the army is keen to project its soft image in an otherwise hostile part of the country.
"The epicentre of the quake was located in the desert, and population centres do not surround it. There were no fatalities in the towns around the epicentre," an Iranian crisis centre official, Morteza Akbarpour, was quoted as saying by the Iranian news agency Isna.
Iran's Fars news agency said the depth of the quake reduced its impact to the size of a magnitude-4.0 tremor on the surface.
All communications to the region have been cut and the Iranian Red Crescent said it was sending 20 search-and-rescue teams to the area.
However, fatalities were soon reported in Pakistan, mostly in the Mashkel district of Balochistan.
Officials said homes had collapsed and army and paramilitary forces were being sent to help the relief effort.
Two military helicopters carrying medical teams were on their way and would have troops in support, they said.
The area has since been shaken by several strong aftershocks including one on Wednesday of magnitude 5.7.
Area where quake struck
- South-east Iranian province of Sistan Baluchistan, near border with Pakistan
- Biggest province in Iran
- Sparsely populated area of mountains and desert
- Epicentre close to cities of Khash (pop 180,000) and Saravan (pop 250,000)
- About 1,700 villages in vicinity of quake, with many houses built of mud bricks
- Many inhabitants live in tents
UN Secretary General Ban Ki-moon issued a statement saying the organisation stood ready to help "if asked to do so" and the US also offered assistance.
The quake was felt over a wide area.
Tuesday's earthquake was about 180 times stronger in energy release than a 6.3-magnitude quake that struck on 10 April near the nuclear plant at Bushehr in south-western Iran. That quake killed at least 37 people and wounded 850.
The Bushehr plant was not damaged by the earlier earthquake, and an official at the Russian firm that built the plant said it had not been damaged by Tuesday's earthquake either, Reuters reported.
Scientists say earthquakes in south-eastern Iran are triggered by the clash between the Arabia and Eurasia tectonic plates, the former of which is pushing north at a rate of several centimetres each year.
In 2003, a 6.6-magnitude quake destroyed much of the south-eastern city of Bam and killed some 26,000 people.