BOGOTA, Colombia (Reuters) -- A rightist death squad murdered 12 civilians in
                  an attack aimed at ousting suspected Marxist rebels from a region around
                  Colombia's main Pacific coast sea port, authorities said Friday.

                  The massacre took place early Thursday in the village of Sabaletas, just outside
                  Buenaventura, the port which handles 60 percent of Colombia's international
                  trade, police said. In a communique sent to local media, a group identifying itself
                  as the "Calima Front" of the United Self-Defense Forces of Colombia -- a
                  nationwide paramilitary alliance known as the AUC -- claimed responsibility for
                  the killings. It said the victims were "plainclothes guerrillas."

                  It also said it had killed 14 other rebels in clashes in the same area, although
                  police and army were unable to confirm that.

                  In a February report, Washington-based rights group Human Rights Watch said
                  it obtained evidence from government investigators and eye-witnesses that the
                  army's Third Brigade, based in the southwest city of Cali, provided weapons and
                  intelligence to the Calima Front.

                  Thursday's massacre came a week after a lone gunmen shot to death truck
                  drivers' union leader Javier Suarez near his home in Buenaventura. Union leaders
                  said they believed he had been killed by paramilitary gunmen.

                  Suarez and other leftist union bosses had organized a wave of strikes over the
                  last three years that have snarled road transport and blocked shipments, including
                  key coffee and sugar exports, out of Buenaventura.