KABUL/PESHAWAR, Pakistan (REUTERS, BLOOMBERG) - A major earthquake struck the remote Afghan northeast on Monday (Oct 26), killing at least 135 people in Afghanistan and nearby northern Pakistan and sending shock waves as far as New Delhi, officials said.

The death toll could climb in coming days because communications were down in much of the rugged Hindu Kush mountain range where the quake was centred.

In one of the worst incidents, at least 12 girls were killed in a stampede to flee their school building in the northeastern Afghan province of Takhar, just west of Badakhshan province where the tremor's epicentre was located.

"They fell under the feet of other students," said Abdul Razaq Zinda, provincial head of the Afghan National Disaster Management Agency, who reported heavy damage in Takhar.

Shockwaves were felt in New Delhi in northern India and across northern Pakistan, where hundreds of people ran out of buildings as the ground rolled beneath them. The quake was also felt in parts of northwest China's Xinjiang province, Xinhua reported. No deaths were reported in India and Xinjiang.

"We were very scared ... We saw people leaving buildings, and we were remembering our God," Pakistani journalist Zubair Khan said by telephone from the Swat Valley northwest of the capital Islamabad. "I was in my car and, when I stopped my car, the car itself was shaking as if someone was pushing it back and forth."

The quake was 213km deep and centred 254km northeast of Kabul in Badakhshan province. The US Geological Survey initially measured the magnitude at 7.7, then revised it down to 7.5.

Just over a decade ago, a 7.6 magnitude quake in another part of northern Pakistan killed about 75,000 people.

In Afghanistan, a total of 33 were reported dead on Monday. In addition to the 12 schoolgirls in Takhar, seven people died in the eastern province of Nangarhar, two in Nuristan province in the northeast, three in eastern Kunar province and nine in Badakhshan, officials said.

Indian Prime Minister Narendra Modi said his country stood ready to offer assistance. "I have asked for an urgent assessment and we stand ready for assistance where required, including Afghanistan & Pakistan," he wrote on Twitter. "I pray for everyone's safety," he added.

Pakistan said its army had begun rescue efforts in the country.

PHONES DOWN

In Pakistan, 102 deaths were reported by early evening, most in northern and northwestern regions bordering Afghanistan, officials told Reuters.

Particularly hard-hit in Pakistan was the northern area of Chitral, where 20 people were killed, police official Shah Jehan said. The death toll was likely to rise because so many areas were cut off from communications, he said.

Journalist Gul Hammad Farooqi, 47, said his house had collapsed. "I was thrown from one side of the road to the other by the strength of the earthquake. I've never experienced anything like it," he said. "There is a great deal of destruction here, and my house has collapsed, but thankfully my children and I escaped."

Further south, the city of Peshawar reported two deaths but at least 150 injured people were being treated at the city's main hospital, the provincial health chief said.

In Afghanistan, international aid agencies working in northern areas reported that cell phone coverage in the affected areas remained down in the hours after the initial quake. "The problem is we just don't know. A lot of the phone lines are still down," said Scott Anderson, deputy head of office for the UN Office for the Coordination of Humanitarian Affairs in Kabul.

Badakhshan provincial governor Shah Waliullah Adib said about 400 houses were destroyed but he had no figures on casualties. "Right now we are collecting information," he said.

The earthquake struck almost exactly six months after Nepal suffered its worst quake on record on Apr 25. Including the toll from a major aftershock in May, 9,000 people lost their lives and 900,000 homes were damaged or destroyed there.

The Hindu Kush mountain region is seismically active, with earthquakes the result of the Indian subcontinent driving into and under the Eurasian landmass. Sudden tectonic shifts can cause enormous and destructive releases of energy.