Business and transportation across much of Colombia's eastern plains and mountains were paralyzed this week in an "armed strike" called by the National Liberation Army (ELN) guerillas. Roads were blocked and commerce ordered suspended by the guerillas starting Sept. 12 in the departments of Arauca, Vichada, Norte de Santander and Casanare. Most affected was Arauca, where vehicles were burned at guerilla roadblocks and authorities suspended school classes. The paro armado was officially lifted after four days, but the ELN has threaetened to resume the strike and expand it to other departments. A recent increase in ELN violence is seen as a guerrila strategy to increase the group's leverage in peace negotiations with the administrations with President Juan Manuel Santos. The talks were announced in 2014, just before Santos' re-election, but have yet failed to enter the formal stage. (Caracol Radio, Sept. 14; Semana, Colombia Reports, Sept. 12)