Federal agents are investigating the construction of explosive devices that rocked a Yakima neighborhood Thursday night, although a police spokesman cautioned the public against overreacting.

“We’re not saying this was done by anarchists,” Yakima police Lt. Nolan Wentz said. “It could be just some kids that are experimenting.”

The incident began around 10:30 p.m. when residents near Yakima Regional Medical and Cardiac Center, as well as several patrol officers in the area, reported a series of loud explosions.

The explosions, five in all, apparently set a bush on fire in the 1100 block of West Chestnut Avenue. A resident, meanwhile, spotted a suspicious-looking device in a carport near the burning bush.

A nearby apartment building was evacuated and a State Patrol bomb squad was brought in. Using a remote-controlled vehicle, the device was detonated without causing injury or property damage.

The device was described as a small plastic water bottle, tightly wrapped with electrical tape and shrouded in bubble-wrap. Wentz said its appearance, coupled with the fire caused by the other explosions, was worrisome enough to warrant a call to the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

That’s because most bombs made from water or pop bottles are capable of making an impressively loud bang but are not usually capable of causing a fire, he said.

“This was a little different configuration,” he said, adding, “At this point we’re still waiting for the ATF to look at (the remnants of the devices) and give us a better idea what we’re dealing with.”

Wentz disputed claims in social media that the unexploded bomb was full of mercury, though he did say there may have been some mercury in it. The location, he said, was probably random.

He urged anyone who sees something suspicious-looking like the device not to touch it and to call 911.

Even pop bottle bombs, if handled ignorantly, are powerful enough to cause serious injury, he said.

“I’d rather have people be cautious than see someone get hurt,” he said. “If you see something, let us know.”