Hooded men in uniforms without insignias on Wednesday shot and killed 12 members of the Awa indigenous group, including five children, on a reserve in a region plagued by the cocaine trade, authorities said.

Indigenous leaders and government officials said the killings took place at 5 a.m. when 10 gunmen opened fire on two houses in the Gran Rosario reserve, about 50 miles inland from the port of Tumaco in Narino state. The reserve has about 1,500 Awa.

The state governor, Antonio Navarro, told The Associated Press that the victims were all related. The attack killed five men, two women, two boys, two girls and a baby. He said two males, a 10-year-old and a 20-year-old, were wounded in the gunfire but fled and survived.

The identity of the killers was not immediately known.

Narino state prosecutor, Alvaro Lara, said the gunmen asked for a woman called "The Matron" about a purported debt.

"Seconds later the armed men began to shoot at anything that moved," Lara said.

In February, Revolutionary Armed Forces of Colombia rebels acknowledged killing eight Awa Indians at a different but nearby reservation for allegedly working as informants for the army.

The area is rife with coca plantations and illegal armed groups — leftist rebels as well as far-right militias, both of whom typically wear uniforms — that process the leaf into cocaine and smuggle it out of Colombia.

Navarro said he could not remember a massacre of so many people in Narino state. He said the survivors described the killers as tall, fair-haired men with mustaches, ruling out local Indians.

The director of operations of Colombia's national police, Gen. Orlando Paez, announced a reward for information leading to the arrest of the killers.

Massacres of the magnitude of Wednesday's have been rare since President Alvaro Uribe first took office in 2002 and far-right militias demobilized in a peace deal with his conservative government.

Some 20,000 Awa live in Narino state, Navarro said.

Colombia is home to more than 1 million members of more than 80 indigenous communities. Indians have suffered disproportionately in Colombia's half century-old conflict. So far this year, at least 75 have been killed.

In a recent interview with the AP, the president of the National Organization of Indigenous Colombians, Luis Evelis Andrade, complained that native groups are routinely caught in the crossfire of a conflict that is not theirs.

They represent a disproportionate part of the Colombians forced to flee their homes and villages to escape fighting.

"The lands they gave us — which are the most inhospitable — are today in dispute by armed groups," he said. The same remote reserves also tend to be prime cultivation spots for coca, he said.