Thousands of Afghans are fleeing Taliban-captured cities in the north, some telling of brutal treatment by the insurgents: bodies left in the streets, girls being kidnapped to become Taliban brides, and young men press-ganged into fighting.

Many have arrived in Kabul just this week, following a five-day Taliban blitz that has seen them seize eight provincial capitals -- some with barely a fight. 

But where there has been resistance, those who fled described harrowing scenes.

"We saw bodies lying near the prison... there were dogs next to them," said Friba, 36, a widow who fled Kunduz Sunday with her six children as the Taliban took the city.

Like many who spoke to AFP, she asked not to be fully identified for fear of reprisal.

The war has gathered pace since early May, when foreign forces began the final stage of a troop withdrawal due to be complete at the end of the month.

During their first stint in power -- from 1996 until the September 11, 2001 attacks that prompted the US-led invasion -- the Taliban earned notoriety for a strict interpretation of Islamic law that punished even petty crime with public floggings and executions.

But they have also been accused of war crimes on this campaign, targeting government officials and security personnel -- particularly in areas where they have met resistance.

- 'He was just a barber' -

"Three days ago the Taliban killed a barber because they thought he was working for the government. But he was just a barber," said Mirwais Khan Amiri, 22, whose car was struck by bullets as he fled Kunduz three days ago.

"They killed people who worked in government even if they had quit four to five years ago."

Another evacuee from Kunduz, Abdulmanan, told AFP the Taliban beheaded his son. 

"They took him... as if he was a sheep and cut off his head with a knife and threw it away," he said.

AFP had no way of independently verifying these reports.

The Taliban routinely deny committing atrocities and last week announced they had set up a WhatsApp hotline to deal with complaints.

But several humanitarian organisations, including the UN, say possible war crimes have been carried out that need to be investigated.

The UN's International Organization for Migration said Tuesday that more than 359,000 people have been displaced by fighting this year alone.

In a public park in central Kabul Tuesday, hundreds of the latest arrivals were camping in the open -- sheltering from the sun in the shade of trees, or under sheets stretched between them.

Occasionally a volunteer would offer food or snacks, causing chaotic scenes as the evacuees clamoured for handouts.

- Forced to marry -

One newcomer, 25-year-old widow Marwa, fled Taloqan on Saturday as fighting raged for the city -- terrified she would be ordered to marry a Taliban fighter.

"I heard my 16-year-old cousin has been forcibly taken by the Taliban for marriage with one of them," she said.

"She was engaged, and her fiance is in France," she added, bursting into tears.

"When there are two girls in a family they take one to marry her to a fighter; when there are two boys they take one to make him fight."

Widow Bibi Ma told AFP how she found her only son Azizullah, 20, dead on her doorstep -- hit by shrapnel from a Taliban rocket.

"After my husband died, my son was everything to me ... our guardian, and source of joy," she said.

"My heart died that moment, it was horrible to see him dead."

Another Azizullah, who worked in the justice department in Kunduz, could find no comfort even in the relative safety of the capital.

"The way they are fighting, without care for others, they will be coming to Kabul soon," he said.

"Where will we have to run to then?"