Taliban fighters stood aboard captured Humvees as they prepared for a parade Wednesday of plundered US military hardware, including possibly a Black Hawk helicopter, in their southern Afghan spiritual heartland.

A long line of green vehicles sat in single file on a highway outside Afghanistan's second-biggest city of Kandahar, many with white-and-black Taliban flags attached to aerials, according to an AFP journalist.

Fighters manned the controls of the multi-purpose trucks -- used by US, NATO and Afghan forces during Afghanistan's 20 years of war -- while others clambered over the vehicles at Ayno Maina, a town on the outskirts of the city.

Pick-up trucks laden with supporters rolled past the convoy of military vehicles, some armed with heavy weapons and machine guns.

At least one Black Hawk helicopter has been seen flying over Kandahar in recent days, suggesting someone from the former Afghan army was at the controls as the Taliban lack qualified pilots.

Kandahar is the ethnic Pashtun heartland of the Taliban where the hardline group was founded and from where it rose to power in 1996. By 2001, when US-led forces invaded, the Taliban had seized control of most of the country.

At Kandahar Cricket Ground, white-bearded Taliban leaders waited in the shade in the players' dugout, reclining on armchairs behind wooden coffee tables as they waited for the parade to start.

Others sat crossed-legged on the grass, while hundreds more gathered in the terrace stand to watch.

The Taliban's secretive supreme leader Hibatullah Akhundzada is living in Kandahar, the group said Sunday, after years in the shadows.

Word had spread that he would make an appearance Wednesday, but he did not show up, leaving the city's new governor to address the crowd.

In footage posted online of the build-up to the event, another helicopter flew overhead trailing a Taliban flag as fighters in headscarves waved beneath.

A day earlier thousands of Taliban faithful had poured onto the streets of Kandahar, waving flags and shouting "God is greatest" in celebration at the final US withdrawal.