BOGOTA, Colombia (AP) _ About 200 paramilitary gunmen killed at least 21 peasants and burned homes and businesses in remote south-central Colombia, a jungle region of traditional rebel control where most farmers grow the plant used to make cocaine.

The armed men dressed in military fatigues entered the town of Puerto Alvira, 185 miles southeast of Bogota, just after noon Monday in four large trucks, said Alan Edmundo Jara, the governor of Meta state. They divided people into groups of men and women, then read names of the condemned off a list.

Some of those singled out were taken to a gas station, then shot in the back of the head, residents told reporters who visited the scene Tuesday with Red Cross workers. The gunmen also bombed the town landing strip and torched a small plane.

The witnesses, refusing to identify themselves for fear of reprisal, said that after the massacre, the gunmen gave people eight days to leave or be killed. Residents gathered their belongings Tuesday and prepared to leave.

Most farmers in the town earn money growing coca, the plant used to make cocaine. Graffiti sprayed on walls near bloodied and charred bodies read ``Colombia Without Guerrillas'' and ``Death to Guerrillas and Coca Growers.'' Other messages offered rebel deserters dlrs 1,500.

Leftist rebels guard drug crops to finance their insurgency, but some of their paramilitary foes are also in the drug trade. Government officials have said the paramilitary push into the region, which began in July, is aimed in part at wresting control of the lucrative business.

Both groups often target civilians they believe are helping the other side. Paramilitary gunmen, who frequently act with the tacit support of the armed forces, killed more than 30 peasants in the nearby town of Mapiripan last July.

The massacre occurred during a visit to Colombia by Brian Sheridan, deputy U.S. secretary of defense for narcotics matters, and the head of the U.S. Southern Command, Gen. Charles Wilhelm. The two visited military bases in the volatile region on Tuesday.