Authorities in Anoka County are investigating after a Metropolitan Mosquito Control District (MMCD) helicopter was struck by a golf ball.

According to the Anoka County Sheriff’s Office, the incident happened around 9:50 a.m. Friday. They say a ball hit and slightly damaged the helicopter as it flew over the Refuge Golf Course in Oak Grove.

The pilot noticed the ball fly at the helicopter and landed, after which they noticed it had been damaged. No word on how extensive the damage was.

The MMCD said in a statement about the incident that the helicopter was under contract by and was applying treatment.

Authorities attempted to identify the person who struck the helicopter, but even with the assistance of the golf course’s staff they were unsuccessful.

While no one was injured, the MMCD issued a statement about the incident, saying in part that the safety of its employees and contractors is its top priority.

“Helicopters are an essential part of Mosquito Control operations, allowing the district to treat for mosquito larvae in large wetlands during the short window between when eggs hatch and when adult mosquitos emerge from the water. Larval control consists of applying dry granules containing a naturally occurring soil bacterium or an insect growth regulator and it is the safest and most effective way to protect the public from disease and annoyance caused by mosquitoes. A list of cities and townships where helicopter treatments are planned is updated daily on the MMCD website,” read the statement from Daniel Huff, in part.