BOGOTA, Jan. 10 (Xinhua) -- Ongoing peace talks between the Colombian government and the National Liberation Army (ELN) guerrilla group hit a snag on Wednesday, after a bilateral ceasefire expired at midnight Tuesday and rebel attacks resumed.

Colombian President Juan Manuel Santos recalled the leading government negotiator Gustavo Bell for consultations in Bogota about what the next step should be. The negotiating teams are in Quito, Ecuador, which is hosting the talks.

"The national government deplores the ELN's decision to resume its terrorist attacks against the civilian population, the armed forces and infrastructure," Santos said in a broadcast.

"We were always willing to extend the ceasefire with that organization and negotiate a new one," he added.

In Quito on Tuesday, the two sides sat down to a fifth round of talks that were to focus on extending the truce that took effect on Oct. 1 of last year.

In the early hours of Wednesday, Colombian oil pipelines in several parts of the country were dynamited, and two marines were injured in an attack on a navy post in Arauquita, a town in northern Arauca department.

Santos described the immediate resumption of attacks as "inexplicable," adding he instructed the armed forces to "take decisive action" in response.

"My commitment to peace will be unswerving, but peace is reached through concrete actions, not just words," said Santos.

The ELN delegation to the talks issued a statement via Twitter, saying "the incidents that took place today occurred amid a complex situation of conflict the country is undergoing."

However, the attacks "should not alter the course of the talks to achieve a political resolution to the conflict," the group said.

Last year, the ELN agreed to dialogue with the government after Colombia's largest guerrilla group, the FARC, successfully negotiated a peace deal with Santos' administration that led to their renouncing armed conflict and joining politics.