A bomb attack killed nine security guards and injured three in northern Algeria near a power facility, officials and Algerian media said Monday.

The security agents were working for the facility operated by Algeria's national electricity provider, Sonelgaz, near Ziama Mansouriah, a locality of the Jijel area, 215 miles east of the capital, Algiers, two local town officials told The Associated Press. The bombing occurred at their housing compound.

The El Watan daily said the bombing late Sunday was preceded by mortar fire on the security agents' housing compound, but the officials could not confirm this.

The Italian company Astaldi runs facilities nearby.

But the two officials denied it also could have been targeted.

They spoke on condition of anonymity because Algerian regulations forbid officials from discussing security matters. They said two of the injured guards were in critical condition at a nearby hospital.

Algerian authorities made no immediate comment on the attack, the second against security agents from the Spas security company in recent years.

The bombing has not been claimed, but it came as Al Qaeda's Algerian offshoot has vowed to step up attacks in the North African country ahead of presidential elections in April.