The Afghan interior ministry on Wednesday, however, insisted the armed group’s attack had been repelled and government forces had control.
“The Taliban presence can be seen at Afghan border along with Pakistan in Chaman and no Afghan [government] forces are there at the Afghan border side,” local administration official Arif Kakar told Al Jazeera.
Kakar confirmed that Pakistan was not currently allowing any goods or people to cross the border at Chaman-Spin Boldak, which is one of the two main border crossings between the South Asian countries.
A video shot by a local witness and seen by Al Jazeera showed the Afghan government flag on the Spin Boldak side of the crossing had been replaced by the white flag of the Taliban, which refers to Afghanistan as the Islamic Emirate of Afghanistan.
The social media was also abuzz with pictures of Taliban fighters looking relaxed in what appeared to be the frontier town.
Its seizure follows days of heavy fighting across Kandahar province, where the government was forced to deploy commandos to prevent the fall of the provincial capital even as the group inched closer to taking the frontier crossing.
In a statement, Taliban spokesman Zabihullah Mujahid assured traders and residents there that their “security is guaranteed”.
“The terrorist Taliban had some movements near the border area … The security forces have repelled the attack,” interior ministry spokesman Tareq Arian told the AFP news agency.
Residents disputed the government’s claims.
“I went to my shop this morning and saw that the Taliban are everywhere. They are in the bazaar, in police headquarters and custom areas. I can also hear the sound of fighting nearby,” said Raz Mohammad, a shopkeeper who works near the border.
With the United States just weeks away from wrapping up its final withdrawal from Afghanistan, the group has swept through much of the country, and the government now holds little more than a constellation of provincial capitals that must largely be resupplied by air.
The Spin Boldak border crossing is one of the most strategically valuable for the Taliban. It provides direct access to Pakistan’s Balochistan province, where the group’s top leadership has been based for decades, along with an unknown number of reserve fighters who regularly enter Afghanistan to help bolster their ranks.
Hours after the crossing fell, an AFP reporter on the Pakistani side saw about 150 Taliban fighters riding on motorcycles, waving their flags, as they demanded to be allowed to cross into Afghanistan.
Balochistan is a favoured destination for fighters regularly heading for medical treatment and hosts many of their families.
An important highway leading from the border connects to Pakistan’s commercial capital Karachi and its sprawling port on the Arabian Sea.
Additional reporting by Saadullah Akhtar in Quetta, Pakistan