A radical Islamic sect has attempted to bomb a presidential rally in northeast Nigeria, just days ahead of the country's first set of elections, authorities said.
Officers killed one suspected member of the feared Boko Haram sect and arrested two others on Tuesday in the attempt to attack Ramat Square in the city of Maiduguri, police said.
The All Nigeria's People Party, a strong opposition group in Nigeria's Muslim north, had planned a presidential rally there, though the party's presidential candidate Ibrahim Shekarau did not attend the event.
Borno state police commissioner Mohammed Abubakar said Boko Haram hoped to attack the rally with locally made explosives, which officers recovered inside a car.
The group previously claimed responsibility for the January 28 assassination of gubernatorial candidate Modu Fannami Gubio, the Borno state candidate of the All Nigeria People's Party.
The commissioner said police have been investigating the radical sect that has terrorised northeast Nigeria in recent months.
Boko Haram - which means "Western education is sacrilege" in the local Hausa language - has campaigned for the implementation of Islamic law. Nigeria, a nation of 150 million people, is divided between the Christian-dominated south and the Muslim north. A dozen states across Nigeria's north already have Islamic law in place, though the area remains under the control of secular state governments.
In December, a website claimed Boko Haram committed a series of Christmas Eve bombings and church attacks in Nigeria that left dozens dead. Authorities said a Baptist pastor and two choir members preparing for a late-night carol service were among the victims.
The group has also been blamed for killing more than a dozen police officers and soldiers manning checkpoints since July. Those attacks have shown accused Haram members' ability to kill at will despite a military and police crackdown, leaving a state police commissioner to acknowledge he cannot guarantee the safety of election officials.
The violence also comes ahead of April elections that many worry could ignite simmering ethnic and religious tensions in a country that became a democracy only a decade ago.