BOGOTA, March 23 (Xinhua) -- Four members of the guerrilla group National Liberation Army (ELN) were killed in an operation in Colombia's northern department of Norte de Santander, the Colombian National Army said on Sunday.

Four rifles and one handgun, as well as explosives, supplies and communications equipment were seized in the raid, the army said on social platform X.

The offensive follows orders to restore stability in the region, where the guerrilla group has stepped up attacks against the civilian population since January.

The rebels' attacks have killed at least 80 people and displaced over 40,000 others.

In response, Colombian President Gustavo Petro declared a "state of internal unrest" in the region to address threats to institutional security. ■