A 69-year-old man armed with a rifle threw incendiary devices at an immigration jail in Washington state early on Saturday morning, then was found dead after four police officers arrived and opened fire, authorities said.

The Tacoma Police Department said the officers responded at about 4 am to the privately run Tacoma Northwest Detention Center, a US Department of Homeland Security detention facility that holds migrants pending deportation proceedings. The detention center has also held immigration-seeking parents separated from their children under President Donald Trump's "zero tolerance" policy, an effort meant to deter illegal immigration.

The shooting took place about six hours after a peaceful rally in front of the detention center, police spokesman Loretta Cool said.

On Saturday night, the Pierce County Medical Examiner's Office identified the man as Willem Van Spronsen of Vashon Island, the Tacoma News-Tribune and the Seattle Times reported.

Police said Van Spronsen caused a vehicle to catch fire and that he attempted to ignite a large propane tank and set buildings on fire. Police said that besides the rifle, he had a satchel and flares.

Police said officers called out to Van Spronsen, and shots were fired.

Cool said all four officers fired their weapons, but she didn't have specific details of what took place. She said the officers weren't wearing body cameras, but the area is covered by surveillance cameras from the detention center. She said she didn't know if the man fired at the officers.