Unidentified assailants set ablaze the residence of a Nigerian Catholic priest in northwest Nigeria, burning one priest to death and shooting and injuring another who tried to escape, shaking faith in the security authorities of Africa's most populous country ahead of scheduled elections.

The motives of the armed attackers, known locally as "bandits," were unknown. But Nigeria's Muslim-dominated north is rife with jihadis who have been fighting to establish a caliphate for some 14 years.

The country's north has also seen kidnappings for ransom and killings by armed gangs recently, amid growing fears that the February 25 presidential election might not be held in certain areas.

What happened to the priests?

The bandits failed to access the residence of Father Isaac Achi in Kafin-Koro village in Niger state in the early hours of Sunday and thus resorted to setting his house ablaze. Another priest, identified as Father Collins, was shot while he tried to flee the burning house, a police spokesman said.

The surviving priest was rushed to the hospital for treatment.

"This is a sad moment. For a priest to be killed in such a manner means that we are not all safe. These terrorists have lost it and drastic action is needed to end this ongoing carnage," Reuters news agency quoted Niger state Governor Sani Bello as saying.

Hours later, bandits carried out a separate attack in the northern Katsina state, shooting a priest and taking hostage five people from a Christian home as they were preparing to attend Sunday mass at a church nearby.

Last June, gunmen attacked a Catholic church in southwestern Nigeria during Sunday Mass, killing dozens of worshippers.