Two masked men ordered bar patrons to the ground, took their wallets and emptied the till, according to a report from Madison police.
Police were called to Players Sports Bar at 2013 Winnebago St. at 12:40 a.m. Wednesday for a report of a robbery.
Witnesses told police the men entered through a back door and sprayed a chemical irritant before fleeing. Madison firefighters were called to help those exposed to the chemical and to ventilate the building.
The men are described as black, 5 feet 9 inches to 5 feet 10 inches tall and weighing 180 to 200 pounds. One was wearing a dark hooded sweatshirt with a black mask from the nose down. He was armed with a handgun. The other was wearing a light hooded sweatshirt and light-colored mask from nose down. He was armed with the chemical spray.