Bogotá, June 4 (NNN-RHC) -- Four policemen were killed in an attack on their patrol in the eastern Colombian state of Arauca, according to a National Police press release.

The policemen were patrolling a rural road and were killed when a roadside bomb exploded, followed by the sound of gunfire.

Colombian Minister of Defense Juan Carlos Pinzon says that the police were lured into an ambush by a phone call and subsequently attacked by the National Liberation Army (ELN) rebel group.

Colombian media has reported that both rebel groups, the ELN and the Colombian Revolutionary Armed Forces (FARC), have been known to operate in the region.

The attack comes at a tense time in Colombia’s peace talks and presidential election. The FARC declared a ceasefire during the elections.

Pinzon said two more policemen were injured in the ambush and they were hospitalized in Arauca city.

The ELN is the second largest guerrilla group in Colombia with some 3,000 members.