BOGOTA, Colombia, Aug 9 (Reuters) - Masked gunmen dragged five Colombian Indians out of their homes and killed them on Wednesday after accusing them of collaborating with left-wing guerrillas, U.N representatives and indigenous leaders said.

The killings in southern province of Narino followed Tuesday's massacre of a family of six in a northern region where crops are grown to manufacture cocaine, the illicit drug that helps fuel Colombia's conflict..

"Five displaced Indians were brutally murdered. Between 4:30 and 5 this morning they were taken out and a few meters away killed... after being accused of being militias," UNHCR refugee agency representative Roberto Meier told reporters.

Meier would not say who was responsible. The army, leftist FARC guerrillas and right-wing paramilitaries have all been accused of killing civilians in the four-decade-old war.

Indigenous leaders said men in masks and camouflage uniforms shot the three men and two women after accusing them of working with the Revolutionary Armed Forces of Colombia or FARC, the largest rebel group that U.S. and Colombian officials charge with terrorism and drug trafficking.

"We ask the state, if the conflict is among the armed groups, don't involve our people," said Doris Puchana, a Awa Indian community governor who was given U.N. protection after officials learned the gunmen had been looking for her.

Colombian President Alvaro Uribe began a second term on Monday after winning re-election thanks mostly to his tough security crackdown, which has reduced violence. Thousands of paramilitaries have demobilized under a peace plan.

But remote rural areas are still racked by conflict as the military battles leftist rebels. Hundreds of paramilitaries have also formed gangs linked to narcotics and extortion.

Colombia's 750,000 indigenous people are often caught up in the country's violence because they live in remote rural regions. At least 32 Indians have been murdered and 5,700 displaced this year, according to Colombia's National Indigenous Organization.

The UNHCR estimates thousands of indigenous people have been displaced by violence in recent months. Nearly 1,700 Awa people were forced from their homes last month in Narino. In April, 1,500 Wounaan Indians fled in northern Choco after gunmen murdered two of their leaders, the agency said.