BOGOTA, Colombia (CNN) -- At least 31 people, most of them civilians,
                  have died in the latest wave of political violence to sweep Colombia,
                  authorities said Monday.

                  An army spokesman said 10 guerrillas were killed Monday in two separate
                  clashes with troops in southern Putumayo and northwest Antioquia
                  provinces.

                  But the worst bloodshed took place Sunday, when right-wing death squads
                  killed at least 21 unarmed civilians in two attacks in northern Colombia.

                  Ten people were killed and 15 abducted in San Carlos in Antioquia, and 11
                  were killed in Altos del Rosario in Bolivar province. Police said the death toll
                  could rise if the abducted villagers had been killed.

                  The attacks on the two villages were widely interpreted as rejections of
                  President Andres Pastrana's peace overtures to leftist rebels, authorities
                  said.

                  Death squads arrived with hit lists

                  Graffiti spray-painted on the walls of the two towns attributed the killings to
                  Colombia's leading ultra-right paramilitary group, the Peasant
                  Self-Defense Force of Cordoba and Uraba (ACCU).

                  In both attacks, heavily armed gunmen dragged civilians from their
                  homes and shot them while other residents watched in horror.

                  The motive was not immediately clear, but paramilitary groups have killed
                  leftists and suspected rebel sympathizers with impunity for years.

                  The mayor of Altos del Rosario, Sen Rodriquez, said the death squad
                  arrived in his town with a list of 40 people. He told Caracol Radio that he
                  and other mayors from the region have been forced to flee to Cartagena, the
                  Bolivar state capital, because of threats from both paramilitary groups and
                  rebels.

                  Rightists deride concessions to rebels

                  Graffiti in Altos del Rosario alluded to Colombia's nascent peace process
                  and what rightists call the "shameful" concessions Pastrana has made to
                  Marxist rebel leaders in a bid to jump-start full negotiations.

                  "Pastrana is twisted," read one of the slogans scrawled across a building in
                  Altos del Rosario.

                  Pastrana has made peace the priority of his nearly 3- month-old government,
                  agreeing to withdraw troops from an area of southern Columbia the size of
                  Switzerland by November 7 to facilitate talks with leftist rebels.

                  He has refused so far to grant the same political status to paramilitary
                  groups, which were first formed more than a decade ago by ranchers and
                  large landholders in response to kidnapping and extortion by rebels.

                  A report published by the Washington-based Human Rights Watch earlier
                  this month said paramilitary groups, often operating with the open or tacit
                  support of the military, were responsible for 60 percent of the most flagrant
                  human rights abuses in Colombia.

                  Colombia's decades-old civil conflict has taken the lives of more than
                  35,000 people, most of them civilians, in the last 10 years alone.

                       The Associated Press and Reuters contributed to this report.