The foundation of the Indian epics is that they are about a time when technology was far beyond what it was when the stories were written down. Here’s a description of the ancient WMDs:
“Gurkha, flying a swift and powerful vimana (fast aircraft)
hurled a single projectile (astra) charged with the power
of the Universe (nuclear device). An incandescent column of
smoke and flame, as bright as ten thousand suns, rose with
all its splendor.
It was an unknown weapon, an iron thunderbolt, a gigantic
messenger of death, which reduced to ashes the entire race
of the Vrishnis and the Andhakas.
The corpses were so burned as to be unrecognizable.
Hair and nails fell out; Pottery broke without apparent cause,
and the birds turned white.
…After a few hours all foodstuffs were infected…
…to escape from this fire the soldiers threw
themselves in streams to wash themselves and their
equipment.” — The Mahabharata