A fire broke out at a military weapons depot overnight on April 18 in Pakistan's Khyber district near the border with Afghanistan.
The army said the blaze at the depot in the Landi Kotal area was the result of an accident.
However, local residents and intelligence officials said they heard gunfire in the middle of the night before the fire broke out.
They said it appeared the military base had come under attack.
A Radio Mashaal correspondent living in the area reported heavy explosions were heard throughout the night.
No injuries were immediately reported.
All schools in the Landi Kotal area were closed on April 18.
The incident happened just a day after the Taliban announced an end to their 40-day long cease-fire with the Pakistani government.