KABUL -  Afghan Vice-President Abdul Rashim Dostum escaped unhurt from an ambush by Taliban insurgents as his convoy returned from overseeing fighting at a northern battlefield, Afghan officials said on Monday.

In their effort to topple the Western-backed government in Kabul, Taliban fighters have battled their way into the outskirts of Lashkar Gah, the capital of the southern province of Helmand, in recent weeks.

Sunday's ambush took place during a frontline visit to Faryab province by Dostum, who has recently been spending more time on his northern home turf than in the capital, Kabul, officials said.

"General Dostum was on the way back from overseeing the fighting when his convoy came under ambush," in the Ghormach district of the province, said Bashir Ahmad Tayanj, a spokesman for Dostum. "Both sides received casualties, but General Dostum was not hurt," he added.

There was no immediate comment from the Taliban. Taliban militants have spread their insurgency from the southern strongholds to the once peaceful northern parts of the country in recent years. Afghan troops launched an operation in Faryab at the weekend as the Taliban fighters have gained ground in remote areas from where they frequently stage attacks on government forces.

Dostum, a war-hardened ethnic Uzbek, was in an armoured vehicle, accompanied by well-armed security forces, when dozens of insurgents attacked the convoy, another official said.  Five men on Dostum's side and several insurgents have been killed, said a security official who did not want to be identified, because he is not authorised to talk to the media.

It is not the first such attack in the same area on Dostum, whose convoy was also targeted last year, when about 20 insurgents opened fire on it.

Dostum, who has close protection from hundreds of bodyguards and leads personal militias, is accused of war crimes by human rights groups.

He joined the political mainstream as President Ashraf Ghani's running mate in bitterly contested presidential elections in 2014.

Since then he has swapped his suit for a military uniform to accompany Afghan security forces and militiamen against the Taliban fighting in his northern heartland.  Afghanistan's government has been investigating alleged abuses by militiamen loyal to Dostum and Atta Mohammad Noor, the acting governor of the northern province of Balkh, following repeated clashes between both sides in recent months.

Areas of the north have descended into chaos and lawlessness, according to a confidential report drafted by the investigators and seen by Reuters in July.

Meanwhile, the Taliban's latest offensives in the north and south of Afghanistan have killed dozens of people and displaced tens of thousands, officials said Monday.

Earlier this month the militants launched a full-fledged attack on Kunduz, briefly entering the northern city and triggering fierce fighting with Afghan forces that forced thousands of residents to flee.

Last week the militants also launched a new attack on Lashkar Gah, the besieged capital of volatile Helmand province in the south.

They killed dozens of security forces personnel before being pushed back when government reinforcements arrived.

"Due to hostilities in Kunduz and intensified fighting across the south we have seen a jump of 37,000 IDPs alone - more than ten percent of the year total in just one week," Danielle Moylan a spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs, told AFP.

The total number of internally displaced people due to fighting since the start of the year stands at 323,500.

In Helmand, which has seen some of the worst fighting since the Taliban began their insurgency against the western-backed Kabul government in 2001, authorities reported dozens of troops had been killed and more captured.

"Around 50 Afghan security forces were killed, and the same numbers went missing in Helmand province over the past two weeks," Tooryalai Hemat, the Helmand governor's adviser, told AFP.

Shir Muhammad Akhunzada, a parliamentarian, told parliament around 70 soldiers had surrendered to the Taliban.

In Uruzgan, another volatile province north of Helmand, 150 soldiers surrendered last week at Tarin Kot, senior local official Mohammad Zahir Naderi said.

"They surrendered with their weapons and ammunition and twenty Humvees," Zahir said, referring to US-built light-armoured vehicles.

The Taliban have intensified attacks across the war-torn country in recent months, pressuring Afghan forces stretched on multiple fronts.

Apart from their assaults on Kunduz and Helmand, they have attempted to overrun other provincial capitals, from Baghlan in the north to Farah in the west, but have so far been repelled.