BOGOTA, Colombia (AP) — An attack on a military base in eastern Colombia killed two soldiers and injured at least 21, Colombia's military said on Tuesday, as tensions escalate between Colombia's government and one of the nation's largest remaining rebel groups.

Colombia's military blamed the National Liberation Army for the attack, with President Gustavo Petro hinting late on Tuesday that the attack will lead to a suspension, or a cancellation of peace talks with the rebel group.

“This is an attack that practically closes a peace process, with blood," Petro said during a ceremony, in which he named a new judge to one of Colombia's highest courts.

The National Liberation Army, or ELN, ended a cease-fire with the Colombian government in August, but is still involved in peace talks aimed at ending more than five decades of conflict.

The army said Tuesday that the group fired homemade rockets from a cargo truck that had been parked near a base in Puerto Jordan, a small town in Colombia's Arauca province.

The ELN was founded in the early 1960s by union leaders and university students inspired by the Cuban Revolution. The group has an estimated 6,000 fighters in Colombia and Venezuela and finances itself through drug trafficking and illegal gold mines.

Recently the ELN has been spreading into rural areas abandoned by the Revolutionary Armed Forces of Colombia, the large rebel group that made a peace deal with Colombia's government in 2016.

After being elected two years ago, President Gustavo Petro quickly launched peace talks with the ELN and several smaller armed groups under a policy known as total peace.

But talks with ELN floundered as the group continued to conduct kidnappings and tax civilians in areas under its control. The ELN has also expressed its frustration with a recent effort by Colombia's government to start separate peace negotiations with one of its splinter groups in southwest Colombia.

A cease-fire between the government and ELN expired at the end of August and was not renewed. Since then, the group has stepped up its attacks on military targets and oil pipelines in Colombia's Arauca province.

In a message published on X, Colombia's defense ministry said it would act with “firmness and resolve to restore security and stability" in Arauca province. ___

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