Oregon Public Broadcasting

Police in Eastern Oregon had to call in a bomb squad Sunday to defuse what they're saying was a "homemade explosive device". The bomb was found near a reservoir west of Vale.

Authorities say the two men, believed to have built it, were gravely injured when another device they brought to the reservoir blew up.

Police aren't yet releasing either man's name -- only that they're 59 and 60 years old and shared a house in Ontario. Ontario Police Chief Mark Alexander says a search of that home turned up more bomb-making materials and literature.

Alexander says as of Sunday night, police hadn't been able to extensively interview either men and that means many questions are still unanswered.

"What were they doing with this? What was their motive and what was their intent? That's something that we'll have to work on through our investigation as it continues," said Alexander.

So far, neither man been charged with a crime. But Alexander says the pair could possibly face both state and federal charges.

He says the Federal Bureau of Alcohol, Tobacco, Firearms and Explosives will take part in the investigation.

This story originally appeared on Oregon Public Broadcasting.