KABUL (AFP) - At least a dozen schoolgirls were trampled to death in the remote northern Afghan province of Takhar, in the most horrifying tragedy to emerge so far from a quake that rocked parts of South Asia on Monday (Oct 26), killing nearly 280 people.

Bystanders rushed the dazed and terrified girls to hospital, many lying limp in the arms of their rescuers, after a deadly stampede broke out as the students tried to flee their classrooms as the quake hit.

"The students rushed to escape the school building in Taluqan city after the terrifying quake, triggering a stampede," Takhar education department chief Enayat Naweed told AFP.

The 12 students of Bibi Hajra high school killed were all under 16.

"When the aggrieved relatives of the dead students came to collect their bodies, they were so distressed that they could not even talk to authorities to record their names," said Hafizullah Safai, head of the Takhar health department.

The powerful 7.5-magnitude quake struck Afghanistan's Hindu Kush region and was felt across parts of South Asia, with fears that the death toll could rise substantially.

Afghan officials have so far confirmed 33 fatalities in the provinces of Badakhshan, where the epicentre was located, as well as in Takhar, Nagarhar and Baghlan.

Given the difficulty in accessing most of these areas because of the rugged terrain, it could be days before the full impact of the quake is known.

"Phone lines are down and communication has been cut off in many areas," said Afghanistan's chief executive Abdullah Abdullah, adding that the quake was the strongest in felt in recent decades.

Officials in Nangarhar said people were trapped under debris in some districts of the volatile province, known as a hotbed for Islamic State in Iraq and Syria (ISIS) insurgents.

"The death toll is expected to keep rising," warned Nangyalay Yousufzai, the head of Nangarhar Red Crescent Society.

Thousands of frightened people rushed into the streets across Afghanistan, Pakistan and India as the quake rocked a swathe of the subcontinent.

Live footage from an Afghan news broadcast filmed in Kabul showed an anchor abandoning his desk as the quake shook the cameras.

The US Geological Survey put the epicentre near Jurm in Badakhshan province, neighbouring Takhar, at a depth of 213.5 km.