Unidentified violent groups on Wednesday burned three cargo trucks on a road linking the town of Ocaña with the city of Cucuta, both in Colombia's northeastern Norte de Santander province, which borders on Venezuela, sources with the National Police confirmed to Efe.

The incident, which occurred at 6 a.m. local time, took place after several individuals intercepted the vehicles and then set the trucks on fire, completely closing down the roadway for several hours.

So far, the perpetrators of the attack are unknown, but evidently operating in the region are elements of the Revolutionary Armed Forces of Colombia, or FARC, the National Liberation Army, or ELN, and the Popular Liberation Army, or EPL.

Nevertheless, local authorities point in particular to the heavy ELN presence, with that rebel group in recent weeks carrying out assorted armed actions in the vicinity.

This strike comes 24 hours after two other attacks were staged in nearby Arauca province, also evidently by the ELN, a conclusion drawn due to their significant presence in that zone.

Early Tuesday morning, eight soldiers were wounded in a rural portion of the town of Saravena when unknown attackers hurled a homemade bomb at them, leaving one of the troops in "very serious" condition, military sources confirmed to Efe.

Shortly thereafter, Pedro Antonio Bohorquez, the secretary for social development in Saravena, was shot to death by assassins who intercepted him as he was preparing to enter the city hall with his bodyguard, who was also killed.

Provincial authorities confirmed that the official had been threatened on numerous occasions by the ELN, which regularly targets Colombia's petroleum infrastructure.

The violent deeds of the guerrilla group, which is holding exploratory peace talks with the Colombian government, have increased since July 4, the 50th anniversary of ELN's founding.

In numerous communiques published since then on its Web page, the ELN characterizes the series of attacks as "commemorative acts" designed to mark the anniversary. EFE