KABUL: Rahim Khan's return to Afghanistan 28 years after fleeing to Pakistan was not the homecoming he had dreamed of.

The 60-year-old is one of a growing number of Afghan refugees making the journey back with trepidation, as militant violence intensifies, yet feeling shunned by their adopted country as relations between the neighbours sour.

The rate of returnees has quadrupled this year, with 137,000 refugees going back to Afghanistan since January.

The number could spike further if the countries fail to agree by December 31 to extend identity cards for two years and allow some 1.5 million registered refugees to stay in Pakistan.

The chill in relations, amid an offensive by Taliban insurgents which Kabul blames partly on Pakistan, has put the extension in doubt, along with the future of another million unregistered Afghans.

"First we had to leave here because of war. Now we are coming back to war and bombs," said Khan, speaking at a refugee centre near Kabul where his Pakistan-born grandchildren were being taught the dangers of mines and roadside bombs.

Outside, the thump of exploding ordnance from a nearby army range echoed off arid hills, another reminder that Afghanistan appears no closer to peace than when Khan left during the Soviet occupation.

The dangers mean thousands of people have fled Afghanistan this year, many of them to Europe where governments are struggling to cope with an influx of migrants from the Middle East and beyond. Yet Khan and others like him say they had little choice but to leave Pakistan.

His son Abdul Manan said their life as labourers and fruit vendors in Azad Kashmir took a dramatic turn for the worse after Taliban gunmen massacred at least 141 students at the Army Public School in Peshawar in December.

Islamabad blamed the atrocity on the Taliban militants based across the border, and anti-Afghan sentiment in Pakistan rose.

Manan said police started showing up at their home, asking to see their papers and threatening them with jail if they failed to pay 1,000-1,500 rupees ($10-15) every few days.

"We decided to leave, there was no other option. We couldn't keep paying 1,500," said Manan. "This is our home and we have no other place to go." Raja Shafqat Khan, a senior official at the police headquarters in Muzaffarabad, administrative capital of Azad Kashmir, said he was not aware of the family's complaints.

"As a policy, we do not harass Afghan refugees," he said.

Pakistan's refugee minister, Abdul Qadir Baloch, promised to renew ID cards if he got cabinet approval, and said Pakistan would "not use any coercive measures" to send Afghans back.

Chill deepens

Afghan President Ashraf Ghani spent much of his first year in office trying to improve relations and spur peace talks with the Taliban, believed to have close links with Pakistan's spy agency.

But efforts stalled and the fledgling peace process collapsed after it was revealed in July that Taliban leader Mullah Omar had died two years earlier.

A spate of lethal attacks in Kabul that Ghani believes were planned by militants hiding on Pakistan's side of the porous, rugged border soured relations further.

Interior Minister Chaudhry Nisar Ali Khan has said he wanted all refugees repatriated.

"The cards will not be extended," he said. "They expire at the end of this year."

There are four months left for the neighbours to patch things up, but for now the mood is hostile.

Since Ghani pointed the finger of blame across the border for the attacks, Pakistani flags and currency have been burnt by protesters. Pakistani diplomats in Kabul say they are restricting their movements.

Seeking to assert itself after Omar's death, and exploiting a reduced foreign troop presence, the Taliban has stepped up its insurgency, leading to hefty clashes with Afghan forces and thousands of casualties.

Khan is moving in with his daughter-in-law's family in the northeastern province of Kunduz, because fighting is too fierce around his farmland in neighbouring Baghlan.

As thousands arrive from Pakistan, others are seeking ways to leave.

Humanitarian organisations estimate that nearly one million Afghans have been internally displaced by fighting, and on the streets of Kabul, conversations quickly turn to departure.

Almost everyone knows someone attempting to get to Europe.

After Syrians and Eritreans, Afghans are the third biggest group of asylum seekers in Europe, making up about 11 per cent of the 300,000 refugees and migrants who have made it across the Mediterranean this year, according to data from the United Nations (UN) refugee agency.

Ahmad Faheem, who runs the agency's Kabul reception centre, said some of those leaving were among 3.5 million former refugees who returned from Pakistan soon after the United States toppled the Taliban in 2001, amid brief hope of a better future.

"Day by day the security situation is getting worse," said Faheem, who himself returned from Pakistan in 2002. "They have come here to try to settle, but if there is no security and no work, they leave again."