By Abdul Qadir Sediqi and Orooj Hakimi

KABUL (Reuters) – Taliban fighters in Afghanistan seized control of a major border crossing with Pakistan on Wednesday, achieving a key strategic objective during a rapid advance across the country as U.S. forces pull out.

A Pakistani official said Taliban insurgents had taken down the Afghan government flag from atop the Friendship Gate at the border crossing between the Pakistani town of Chaman and the Afghan town of Wesh.

The crossing, south of Afghanistan’s main southern city Kandahar, is the landlocked country’s second busiest entry point and main commercial artery between its sprawling southwest region and Pakistani sea ports. Afghan government data indicate that the route is used by 900 trucks a day.

The Taliban takeover forced Pakistan to seal parts of its border with Afghanistan after heavy fighting between insurgent and Afghan government forces around Wesh.

Afghan officials said government forces had pushed back the Taliban and were in control of the Spin Boldak border district in Kandahar province. But civilians and Pakistani officials said the Taliban controlled the Wesh border crossing.

“Wesh, which has great importance in Afghan trade with Pakistan and other countries, has been captured by the Taliban,” said a Pakistani security official deployed at the border area. A Taliban spokesman confirmed Wesh’s capture by the insurgents.

Officials in Chaman said the Taliban had suspended all travel through the gate.

The Taliban have in recent days seized other major border crossings, in Herat, Farah and Kunduz provinces in the north and west. Control of border posts allows the Taliban to collect revenue, said Shafiqullah Attai, chairman of the Afghanistan Chamber of Commerce and Investment in the capital Kabul.

“Income has started to go to the Taliban,” Attai told Reuters, though he could not estimate how much they were earning.

The Taliban, who ruled Afghanistan with an iron fist from 1996 until their ouster in 2001 by a U.S. invasion following the Sept. 11, 2001 attacks on the United States, have been fighting since to topple the Western-backed government in Kabul.

Emboldened by the departure of foreign forces by a September target, with peace talks stalled, they are making a fresh push to surround cities and capture territory.

PRESIDENT VOWS TO BREAK TALIBAN BACKBONE

President Ashraf Ghani travelled to the northern province of Balkh on Tuesday to assess security after the Taliban pushed government forces out of several districts there.

Ghani, 72, met civilians and assured them that “the Taliban’s backbone will be broken” and government forces would soon retake all of the areas lost to the militants, the Tolo News network reported.

In the western province of Herat, a security official said Taliban fighters had fired several mortars at the Salma Dam, a vital hydroelectric and irrigation project.

Officials at the National Water Affairs Regulation Authority appealed to the Taliban to treat the dam as a “national treasure (that) is the common property of all and should not be damaged in military conflict”.

The Indian-financed dam generates over 40 megawatts of power and helps irrigate over 75,000 hectares of land in the region.

Vice President Amrullah Saleh said the Taliban were forcing members of a small ethnic minority to either convert to Islam or leave their homes in the northern province of Badakhshan.

“These are minority Kerghiz who lived there for centuries…They are now (across the border) in Tajikistan awaiting their fate,” he said on Twitter.

The United Nations mission in Afghanistan said it was increasingly concerned about reports of rights abuses as the fighting spreads. “The reports of killing, ill-treatment, persecution and discrimination are widespread and disturbing, creating fear and insecurity,” the mission said in a statement.

Educated Afghans – especially women and girls who were barred from school and most work under Taliban rule – have voiced alarm at their rapid advance, as have members of ethnic and sectarian minorities persecuted under the Taliban’s severe interpretation of Sunni Islam.

Taliban spokespeople reject accusations that they abuse rights, and say women will not be mistreated if the Taliban return to power.

“The best way to end harm to civilians is for peace talks to be reinvigorated in order for a negotiated settlement to be reached,” the U.N. mission said.

The Taliban made a commitment to negotiate with their Afghan rivals as part of an agreement under which the United States offered to withdraw its forces. But little progress has been made towards a ceasefire in several rounds of talks in Qatar.

Senior politicians from Kabul were preparing to leave for Qatar for more talks this month as Western diplomats urged the rival sides to work towards a power-sharing agreement.

(Additional reporting by Gul Yosuefzai in Quetta, Gibran Peshimam in Islamabad; Writing by Rupam Jain; Editing by Robert Birsel and Mark Heinrich)