Authorities in Michigan are hunting for two jet skiers who they say ran over a flock of geese on a lake last week — killing one animal and injuring several others.

The state Department of Natural Resources says the disturbing incident happened at about 2 p.m. July 10 on Mona Lake in Muskegon County. Witnesses said two people on personal watercraft drove in circles around the flock of Canada geese before plowing through the animals. At least one of the animals was later found dead.

“The DNR takes any abuse of Michigan’s natural resources seriously,” Lt. Gerald Thayer, a supervisor for the department’s Law Enforcement Division, said in a statement. “It’s important we identify the suspects involved in this incident so justice is served.”

Witnesses described the operators of the jet skis as white, one of whom had long hair. One of their jet skis was purple while the other was white and yellow, Thayer said.

Killing geese illegally is a misdemeanor punishable by up to 90 days in jail and fines of up to $500, authorities said.