A Ferguson, Mo., police officer was shot on Saturday night, in an altercation that authorities said was unrelated to continuing protests over the death of a teenager shot by a police officer there last month.

The officer was shot around 9:10 p.m. while checking on a community center, the Ferguson police chief, Thomas Jackson, said in a brief press conference Sunday morning. The center is not near where the protesters had gathered.

The officer spotted two men, who began running when he approached them, Chief Jackson said. The officer chased them, and as he closed in on one of the suspects, Chief Jackson said, the second suspect pulled out a gun and fired at the officer, who was shot in one arm.

The officer said he fired several shots in return, but there was no indication that he hit either of the suspects, Chief Jackson said.