The remote region in Nangarhar province was most famously used by al Qaeda leader Osama bin Laden in late 2001, in a bid to hold out against the US troops and Afghan allies who toppled the Taliban regime.
Now Afghan officials say Islamic State militants have seized cave complexes in Tora Bora, after days of fighting against Taliban who had been based there.
"Those areas around Tora Bora were a Taliban stronghold, but now Daesh militants captured them during fighting," the police commander in the area, Shah Wali, told Reuters, using an Arabic term for Islamic State.
Taliban spokesman Zabihullah Mujahid acknowledged that Islamic State forces had managed to capture several villages, but he denied that they had seized Tora Bora.