A scuba diver made an unexpected discovery while exploring the depths of a south-central Oklahoma lake: a tear gas grenade that turned out to be live, authorities said.

The man who found the grenade in the Marietta Landing area of the 5,700-acre Lake Murray thought he'd located "some type of bomb," the Love County Sheriff's Office said in a Facebook post.

"(Deputies) and an officer with (the) Lighthorse Police Department arrived on scene and were able to confirm the device found was a live CS gas grenade," Sheriff Andy Cumberledge said in the post.

The Oklahoma Highway Patrol's bomb squad also confirmed the grenade's live status, according to Cumberledge.

The bomb squad dated the device, a gray can labeled "M7A3 Riot CS," to the early 2000s.

"Their team collected the grenade and will detonate and destroy it offsite at a later date," Cumberledge said.

The Army describes the type of device the diver found as a riot control hand grenade.

M7A3 grenades are filled with CS gas and are "designed to control counterinsurgencies and for other tactical missions," according to the Army.

The Love County Sheriff's Office praised the diver for reporting the discovery of the hand grenade.

"This is a great example of a citizen locating something they knew to be dangerous and contacting (authorities) so that it could be disposed of properly," Cumberledge said.