A powerful 7.5 magnitude earthquake which rocked parts of South Asia killed more than 160 people Monday, including 12 Afghan girls crushed in a stampede as they fled their collapsing school.

At least 1,000 more were injured and hundreds of homes destroyed as the quake shook a swathe of the subcontinent, sending thousands of frightened people rushing into the streets in Afghanistan, Pakistan and India.

It was centred near Jurm in northeast Afghanistan, 250 kilometres (160 miles) from the capital Kabul and at a depth of 213.5 kilometres, the US Geological Survey said.

"Initial reports show a big loss of life, huge financial losses in Badakhshan, Takhar, Nangarhar, Kunar and other regions, including the capital Kabul," said Afghanistan's chief executive Abdullah Abdullah.

At least 31 people were confirmed dead in Afghanistan and 135 in Pakistan, according to officials, with the toll set to rise.

"Exact numbers are not known because phone lines are down and communication has been cut off in many areas," Abdullah said, adding that the government has asked aid agencies for relief.

"The quake wrecked huge devastation in some districts," said the governor of Badakhshan province, Shah Wali Adib. "So far 1,500 homes are reported to be damaged or destroyed."

The epicentre was just a few hundred kilometres from the site of a 7.6 magnitude quake that struck in October 2005, killing more than 75,000 people and displacing some 3.5 million more, although that quake was much shallower.

Horrifying news emerged of at least 12 schoolgirls being trampled to death in a northern Afghan province.

"The students rushed to escape the school building in Taluqan city (capital of Takhar), triggering a stampede," Takhar education department chief Enayat Naweed told AFP.

"Twelve students, all minors, were killed and 35 others were injured."

'Very powerful'

The quake, which lasted at least one minute, shook buildings in Kabul, Islamabad and New Delhi.

At least 31 people were killed in Afghanistan including the 12 schoolgirls, officials said.

The toll included nine in Badakhshan province near the epicentre; eight in Nangarhar province bordering Pakistan, and at least two in northern Baghlan province, according to local officials.

In Pakistan at least 135 people had been killed, according to a tally from local and provincial officials.

The military put the toll at 123 with 956 injured, and the National Disaster Management Authority put the official death toll at 43, but said it was checking unconfirmed reports of more deaths.

One aftershock hit shortly afterwards, with the USGS putting its magnitude at 4.8.

In a statistical prediction on its website, the agency said there was a one-third chance of the number of fatalities climbing to between 100 and 1,000 people, with several million dollars' worth of damage likely caused.

The rescue effort was being complicated by the lack of communications, with the region's already fragile infrastructure hit.

Gul Mohammad Bidar, deputy governor of Badakhshan in Afghanistan, told AFP lines were down and it was difficult to reach stricken communities.

"The earthquake was very powerful -- buildings have been damaged (in Faizabad) and there are possible casualties," he said.

Pakistan mobilised its troops and all military hospitals have been put on high alert, army spokesman Lieutenant General Asim Bajwa said, adding that specialised earthquake rescue machinery and army helicopters were being readied for use.

The Pakistan air force said it was offering full support to the National Disaster Management Authority.

Arbab Muhammad Asim, district mayor for Pakistan's northwestern city of Peshawar, said more than 100 people had been injured there alone.

"Many houses and buildings have collapsed in the city," he said.

Dr Muhammad Sadiq, the head of emergency services at a government hospital in Peshawar said the injured were still being brought in.

"Many are still under rubble," Sadiq told AFP.

"I have never seen such a massive earthquake in my life, it was huge," 87-year-old Mohammad Rehman told AFP from Peshawar.

Panicked residents

Traffic came to a halt in downtown Kabul, with frightened people getting out of their cars as they waited for the quake to stop.

Restaurants and office buildings emptied in Islamabad, with cracks appearing in some buildings but no major damage reported. Hundreds in north India poured onto the streets from office blocks, hospitals and homes.

Delhi's metro ground to a halt during the tremor although the airport continued operating.

In the Kashmir region, panicked residents evacuated buildings and children were seen huddling together outside their school in the main city of Srinagar.

Indian Prime Minister Narendra Modi took to Twitter immediately after the quake.

"Heard about strong earthquake in Afghanistan-Pakistan region whose tremors have been felt in parts of India. I pray for everyone's safety," he wrote, adding that India stood ready to assist, including in Afghanistan and Pakistan if required.

Afghanistan is frequently hit by earthquakes, especially in the Hindu Kush mountain range, which lies near the junction of the Eurasian and Indian tectonic plates.

South Asia's quakes occur along a major fault line between the two plates -- one under India pushing north and east at a rate of about two centimetres (0.8 inches) per year against the other, which carries Europe and Asia.

In Nepal twin quakes in May killed more than 8,900 people, triggered landslides and destroyed half a million homes.