McAlester, Okla. ? Feverishly shivering and coughing as if afflicted with pneumonic plague, more than 10,000 people received fake doses from masked hospital workers Saturday in the second day of a three-day bioterrorism drill.

People in this eastern Oklahoma town of 18,000 lined up at a Wal-Mart, health department office and convention center to get plastic packets of jelly beans labeled Cipro and doxycycline.

Boy Scouts and other volunteers were taken by ambulance to the health center and whisked to a triage area or operating tables by hospital workers in yellow gowns and face masks.

Some participants pretended they had succumbed to the lung-attacking disease and went to a makeshift morgue  a refrigerated tractor-trailer rig by the hospital.

The drill, prompted by the Sept. 11 terrorist attacks and the anthrax scare last fall, is one of the nation’s most complex bioterrorism exercises, said Dr. Timothy Cathey, medical director for the Pittsburg County Health Department.

“If we can minimize the impact of an attack, our enemies might decide it’s just not worth the effort,” he said.

The drill began Friday when a plane buzzed low across the city, pretending to release a fine spray containing pneumonic plague. Participants in the drill imagined that 95 percent of McAlester’s population was infected and that 120 people were killed by Saturday afternoon.

Police and health officials set up triage and medicine distribution centers around town Saturday morning, when a weather siren and radio address announced the drill.

Residents of the city were given information about developing family disaster plans when they picked up the fake antibiotics.

In a real attack, the bulk of the medicine would come from the National Pharmaceutical Stockpile  secret stashes of medicine at locations throughout the United States.

McAlester officials put in a mock request for the antibiotics and a National Guard unit in Oklahoma City planned to practice flying supplies to McAlester.