Murder hornets better watch out — the bees are showing they can still be killers.

An aggressive swarm of bees fatally attacked three dogs in Arizona, fire officials said Wednesday.

Firefighters responded to a home in Tucson and first sprayed foam at the swarm to stop their attack.

“Crews are foaming the aggressive bees before tending to the other dogs. We never enjoy killing precious bees, but in these rare cases it is necessary,” the Tucson Fire Department tweeted during its response.

The dogs were taken to a veterinarian, but died shortly after arriving, the department said.

The department urged residents to “be mindful of your animals always, but particularly when there are bees on your property.”

The deadly bee attack comes less than two weeks after it was reported deadly hornets from Asia that measure up to 2 inches long were found for the first time in the US

The aggressive insects, nicknamed “murder hornets,” can wipe out bee colonies within hours and have stingers long and powerful enough to puncture beekeeping suits.