KABUL - Afghan forces have pulled back from strongpoints in the southern province of Uruzgan, continuing a withdrawal which began last month when they abandoned two districts in the neighbouring province of Helmand to the Taliban, officials said on Tuesday.

Provincial government spokesman Dost Mohammad Nayab said around 100 troops and police had been pulled from checkpoints in two areas in Shahidi Hassas district and sent to the neighbouring district of Deh Rawud.

The Afghan Taliban, seeking to topple the Western-backed government in Kabul and reimpose Islamic rule 15 years after they were ousted from power, said the move, which came after heavy fighting late on Monday, had left the entire area around the village of Yakhdan under their control.

The decision to leave the posts follows months of heavy fighting with the Taliban, who have put government forces under heavy pressure across southern Afghanistan.

"We want to create a reserve battalion in Deh Rawud and we may ask our soldiers and policemen from other districts also to leave their checkpoints," Nayab said.

Nayab said the withdrawal was prompted by a shortage of troops and police, worn down by combat losses and desertions.

He said troop numbers in the province were about 1,000 short of their assigned strength while police were hundreds short.

"Some of them have left the army and police, some have been killed or wounded and some have surrendered to the Taliban," he said. "We have to control situation here until we receive enough forces."

NATO officials have long pressed Afghan commanders to pull troops off isolated and hard-to-defend checkpoints and use them more effectively against the Taliban, who have pressed their insurgency since international troops ended most combat operations in 2014.

Uruzgan, which shares a border with the insurgent heartlands of Helmand and Kandahar, is a poor and largely mountainous region which Dutch and Australian troops struggled to stabilize after the Taliban regime was toppled by US-led forces in 2001.

Along with northern Helmand, much of which has been abandoned to the Taliban, it constitutes one of Afghanistan's main opium smuggling routes, providing a significant source of revenue for the insurgency.

Last month, troops pulled out of the Helmand districts of Musa Qalah and Nawzad, regrouping around a few towns near the provincial capital Lashkar Gah in what authorities said was a tactical decision to deploy forces more effectively.

Meanwhile, Human Rights Watch has slammed "virginity exams" conducted on Afghan women and girls accused of so-called moral crimes, saying the invasive tests by government doctors were tantamount to sexual assault.

Women face growing levels of violence and harassment in Afghanistan more than 14 years after the Taliban regime was toppled from power by a 2001 US-led invasion.

Of 53 women and girls as young as 13 accused of pre-marital sex - punishable by up to 15 years in jail - 48 were subjected to virginity exams, Afghanistan's Independent Human Rights Commission found in a recent study.

Nearly half of them were examined more than once, often in the presence of multiple people, according to the study which was highlighted in a new HRW report on Monday.