More than a dozen attackers firing assault rifles killed four police officers and two other people Tuesday in robbing a cash shipment that had just arrived by helicopter, officials said.
The regional police chief blamed leftist rebels.
In another attack Tuesday in a different region, presumed rebels killed a soldier and a civilian motorcycle rider in an attack on a military checkpoint just minutes before a convoy carrying U.S. and U.N. officials passed by.
The robbery occurred about 10 a.m. after the civilian aircraft landed on a soccer field used as a landing pad in the southwestern city of Caloto to deliver the money, Cauca provincial Gov. Guillermo Gonzalez told The Associated Press by telephone.
After the helicopter was unloaded and took off, robbers opened fire from nearby underbrush, killing the four officers and a bank employee who had received the money, Gonzalez said.
Doctors said a 31-year-old female passer-by was shot in the head and died later at a hospital.
Spokeswoman Nora Solorzano of the state bank Banco Agrario, which was receiving the money, said it belonged to Accion Social, the state social welfare agency.
Officials did not disclose the amount stolen.
There were no arrests and the Cauca province police chief Col. Carlos Rodriguez, blamed the 6th Front of the leftist Revolutionary Armed Forces of Colombia, or FARC.
He told reporters that between 15 and 18 rebels, wearing camouflage uniforms, hid in two homes near the soccer pitch before mounting that attack.
In the other shootout Tuesday, Accion Social's director, Diego Molano, was in the six-vehicle convoy that passed the military checkpoint in the Uraba region of Antioquia near Panama shortly after it was attacked.
No one in the convoy was hurt. Among its passengers were a U.S. Agency for International Development official and a delegate from the International Organization for Migration.
Associated Press Writer Vivian Sequera contributed to this report.