As a string of Taliban victories show Afghan government forces in disarray, a young general is advancing his reputation on the battlefield and on social media.

Provincial cities in the north have fallen like dominoes this week -- in some cases after government forces retreated or surrendered without a fight -- but in Lashkar Gah, a Taliban heartland, the army appears to be providing stiffer resistance.

Leading them is Sami Sadat, 36, the highest-ranking army officer in southern Afghanistan, in an intense fight in defence of a provincial capital the Taliban are desperate to seize.

And as the insurgents flood social media with images of surrendering Afghan soldiers and snap selfies with locals, the young general is also using Twitter and Facebook as a slick PR tool in the fight against the hardline islamists.

Sami Sadat is the highest-ranking army officer in southern Afghanistan -- and is leveraging social weapon in the fight against the Taliban
Sami Sadat is the highest-ranking army officer in southern Afghanistan -- and is leveraging social weapon in the fight against the Taliban Public Relation Office of 215 Maiwand corps / HANDOUT

He and the 20,000 men under his command in the 215th Corps have garnered thousands of followers, with their Twitter accounts awash with images of the general among the troops, posing for selfies with young civilians, and meeting local shopkeepers.

On Wednesday the defence ministry tweeted he had been promoted to lead the country's special forces, an announcement widely applauded on the platform.

Sadat remains optimistic despite the Taliban's advances.

"Because I know we are going to win," he told AFP in a phone interview from the frontlines of Lashkar Gah.

"I know this is our country, that the Taliban are failing, that they will fail sooner or later."

Sadat and the 20,000 men under his command in the 215th Corps have garnered thousands of followers
Sadat and the 20,000 men under his command in the 215th Corps have garnered thousands of followers Public Relation Office of 215 Maiwand corps / HANDOUT

But there is more to him than meets the eye, say fellow officers and friends.

"He is anything but naive," said a security official who asked not to be named.

"He has a very strategic vision and a very deep analysis of what is happening," said a general who was Sadat's colleague at the spy agency.

A graduate of the prestigious King's College in London, Sadat began his military career at the Afghan interior ministry.

The loyalty and respect Sadat appears to command among the troops have been a key factor in the resistance to the Taliban in the city, despite their morale-damaging advances elsewhere in Afghanistan
The loyalty and respect Sadat appears to command among the troops have been a key factor in the resistance to the Taliban in the city, despite their morale-damaging advances elsewhere in Afghanistan Public Relation Office of 215 Maiwand corps / HANDOUT

He received military training in Germany, Britain, Poland and the United States, and also served in the National Directorate of Security -- Afghanistan's spy agency.

Sadat prefers to talk about his men rather than himself and family -- senior officers and their relatives are particular targets for Taliban hit squads -- and declines even to say where he was born.

But he is also keen to talk about the war, which he does confidently -- and ruthlessly.

"Any Taliban who comes to Lashkar Gah will die or leave disabled for life," he told AFP.

Still, he admits it will take time to fully secure the city.

On August 4, Sadat called on residents to leave Lashkar Gah so the military could launch an all-out counteroffensive.

But he has still held back, saying he is fearful of hurting those who chose to stay behind.

Sadat described how his forces were going house-to-house to secure neighbourhoods that the Taliban had infiltrated in Lashkar Gah.

"We still find civilians -- especially the elderly and trapped women -- who we take to safer places," he said.

NGOs and the United Nations have repeatedly expressed concern about the violence and the risks incurred by civilians -- threats that include aerial bombardment of suspected Taliban positions in Lashkar Gah by the Afghan military.

The loyalty and respect Sadat appears to command among the troops have been a key factor in the resistance to the Taliban in the city, despite their morale-damaging advances elsewhere in Afghanistan.

"He is not someone who gives orders from the rear while hiding in the humvee," an Afghan security source said.

"He will do anything for his soldiers".