PULLMAN, Washington (AP) — Police are investigating improvised explosive devices and a fire believed to be arson in towns along the Washington-Idaho state line, officials said.

A fire damaged a laser tag arena before 2 a.m. Sunday in Pullman, Washington, The Spokesman-Review reported Monday.

Hours later, an explosive that appeared to be a pipe bomb was found at sports fields in the city.

Last week, an explosive device that looked like a large, M-80 type of firework was found in a mobile home court in Moscow, Idaho, nine miles east of Pullman.

No arrests had been made by Monday and it is unclear whether the events were connected, authorities said.

“We’re asking the same questions,” Pullman police Cmdr. Chris Tennant said. “We don’t have any answers yet.”

Police and fire personnel responded with FBI agents to the report of the explosive in Moscow.

The Spokane Explosive Disposal Unit arrived later and determined the device was active before officers disabled it.

The laser tag building fire was spotted by a Pullman fire department paramedic driving past, Mayor Glenn Johnson said in a statement.

After firefighters doused the blaze, investigators found several ignition points inside the building, as well as evidence of vandalism, Johnson said.

The explosive in Pullman was found beside electrical panels near a walking and bike path.

“Evidence was found at the scene of attempts to light the fuse,” Pullman police Chief Jenkins said in a statement.