KABUL (REUTERS) - Taleban insurgents tightened their grip on captured Afghan territory on Tuesday (Aug 10) as civilians hid in their homes, with an EU official saying the militants now controlled 65 per cent of the country after a string of sudden gains as foreign forces pull out.

President Ashraf Ghani called on regional strongmen to support his government, while a UN official said advances made in human rights in the 20 years since the hardline Islamists were ousted from power were in danger of being erased.

In the capital Kabul, Mr Ghani's aides said he was seeking help from regional militias he has squabbled with over the years to rally to the defence of his government. He also appealed to civilians to defend the country's "democratic fabric", aides said.

In the town of Aibak, capital of Samangan province on the main road between Mazar-i-Sharif and the national capital, Kabul, Taleban fighters were consolidating their control, moving into government buildings, residents said.

Most government security forces appeared to have withdrawn.

"The only way is self-imposed house arrest or to find a way to leave for Kabul," said Mr Sher Mohamed Abbas, a provincial tax officer, when asked about living conditions in Aibak.

"But then even Kabul is not a safe option anymore," said Mr Abbas, the sole bread winner for a family of nine.

Mr Abbas said Taleban had arrived at his office and told workers to go home. He and other residents said they had not seen nor heard fighting on Tuesday.

For years, the north was the most peaceful part of the country with only minimal Taleban presence.

The militants' strategy appears to be to take the north, as well as main border crossings in the north, west and south, and then close in on Kabul.

The Taleban, battling to defeat the US-backed government and reimpose strict Islamic law, swept into Aibak on Monday meeting little resistance.

Taleban forces now control 65 per cent of Afghan territory, are threatening to take 11 provincial capitals and are trying to deprive Kabul of its traditional support from national forces in the north, a senior EU official said on Tuesday.

The government has withdrawn forces from hard-to-defend rural districts to focus on holding major population centres while officials have appealed for pressure on neighbouring Pakistan to stop Taleban reinforcements and supplies flowing over the porous border. Pakistan denies backing the Taleban.

The United States has been carrying out air strikes in support of government troops but said it was up to Afghan forces to defend their country.

"It's their struggle," Mr John Kirby, a Pentagon spokesperson, told reporters on Monday.

Taleban and government officials have confirmed that the Islamists have overrun six provincial capitals in recent days in the north, west and south.

Security forces in Pul-e-Khumri, capital of Baghlan province, to the southeast of Aibak, were surrounded as the Taleban closed in on the town at a main junction on the road to Kabul, a security official said.

Mr Gulam Bahauddin Jailani, head of the national disaster authority, told Reuters fighting was going on in 25 of the 34 provinces and 60,000 families had been displaced over the past two months, with most seeking refuge in Kabul.

About 400,000 Afghans have been displaced in recent months and there has been an increase in numbers of people fleeing to Iran over the past 10 days, the EU official said.

A resident of Farah, the capital and largest city of Farah province in the west near the border with Iran, said the Taleban had taken control of the governor's compound and there was heavy fighting between the Taleban and government forces.

Civilians said the Taleban had captured all key government buildings in the city.

UN human rights chief Michelle Bachelet said reports of violations that could amount to war crimes and crimes against humanity were emerging, including "deeply disturbing reports" of the summary execution of surrendering government troops.

"People rightly fear that a seizure of power by the Taleban will erase the human rights gains of the past two decades," she said.

The Taleban, ousted in the weeks after the Sept 11, 2001, attacks on the United States, appeared to be in a position to advance from different directions on Mazar-i-Sharif. Its fall would deal a devastating blow to Ghani's government.

Mr Atta Mohammad Noor, a northern militia commander, vowed to fight to the end, saying there would be "resistance until the last drop of my blood".

"I prefer dying in dignity than dying in despair," he said on Twitter.

India sent a flight to the city to take its citizens home, its embassy said, asking Indians to leave. The United States and Britain have already advised their citizens to leave Afghanistan.

The United States will complete the withdrawal of its forces at the end of this month under a deal with the Taleban, which included the withdrawal of foreign forces in exchange for Taleban promises to prevent Afghanistan being used for international terrorism.

The Taleban promised not to attack foreign forces as they withdraw but did not agree to a ceasefire with the government.