Authorities in Colombia are struggling to restore power to a major port city after a rebel attack left its 400,000 residents in the dark.

Guerrillas of the Revolutionary Armed Forces of Colombia over the weekend bombed an electricity tower outside the city of Buenaventura. The attack followed a decision by the rebels to end a unilateral cease-fire they declared in December to give space for peace talks with the government.

Authorities said Tuesday that heavy rains and land mines left by the guerrillas are making it hard for security forces to guard the area around the tower site so work crews can repair the damage.

Officials say it will likely be Friday before they can end the blackout, which is hurting businesses and slowing traffic at Colombia's biggest Pacific port.