The Taliban militant group has captured the center of a strategic district in Afghanistan's southern Helmand, forcing government troops to pull out of the area.

The Sangin district’s police chief, Mohammad Rasoul, confirmed the militant group overran the district’s center on Thursday, hours after Afghan army and police units withdrew from the area.

Taliban spokesman Qari Yousuf Ahmadi also issued a statement to announce the capture of Sangin, once considered the deadliest battlefield for British and US troops in Afghanistan. 

Rasoul further said that at the time of the Taliban siege, there were only eight policemen and 30 Afghan soldiers on duty.

He said the security forces were now amassing nearby for “preparing our reinforcements to recapture the district,” without saying when the counterattack would occur and how many forces would be involved.

In the capital, Kabul, a lawmaker from the captured district, Mohammad Hashim Alokzai, urged the military to move quickly to retake of Sangin. He said Sangin’s fall could have devastating consequences for Helmand Province.

The Taliban already controls several major districts in Helmand, where the provincial capital of Lashkar Gah has in the past months been the scene of constant and heavy attacks by the militant group.

Sangin District was once considered the deadliest battlefield for British and US troops in Afghanistan.

The British took over southern Helmand in 2006. Most of Britain’s more than 400 military deaths occurred in Helmand Province — in Sangin alone, Britain lost 104 soldiers.

The development comes amid a surge in Taliban assaults against civilians in recent weeks. The militant group steps up such attacks in the run-up to and during the spring every year as part of a special offensive.

NATO: Russia may be helping Taliban

Meanwhile, a top US commander in Europe accused Russia on Thursday of helping supply the Taliban in Afghanistan.

“I’ve seen the influence of Russia of late—increased influence in terms of association and perhaps even supply to the Taliban,” said Army General Curtis Scaparrotti, who is also NATO’s Supreme Allied Commander.

The commander did not elaborate on what kinds of supplies might be headed to the militants.

However, Russia dismissed the allegation as “a lie” on Friday, saying the claim was an attempt by Washington to try to cover up for the failure of its own policies in Afghanistan, the RIA news agency reported.

Afghanistan faces many security challenges years after the US and its allies invaded the country in 2001 as part of Washington’s so-called war on terror. The offensive removed the Taliban from power, but many areas in the country are still beset with insecurity.