An army unit of Udaipur had held a firing exercise a fortnight ago in the area, a senior police official said.
The couple have left behind seven children, including four girls.
"Some army unit from Udaipur had held a firing exercise a fortnight ago, and left behind some grenade (used and unused) which the couple may have tried to rip apart to get some metal for sale," Superintendent of Police Sirohi, Rajiv Parcha, said.
There children were looking for them at their relatives' places as they did not return home after two days.
More From This Section
Today afternoon, some passersby found the bodies of the couple and informed the police.
The bodies were highly decomposed and their limbs were blown apart, the SP said, adding the post mortem examination was done on the spot.
The police have also called army officials from Udaipur and Mount Abu, and forensic experts to verify the exact cause of deaths, the SP said.