Nigerian officials said attackers on Monday stabbed eight people to death in a central region beset by religious and ethnic tensions, while police in the restive northeast said members of a Muslim sect attempted to drive a car loaded with explosives into a busy police station.
The separate attacks on Monday underscore the fragile security and religious tensions in Africa's most populous nation, which is almost evenly split between Muslims in the north and the predominantly Christian south.
Captain Charles Ekeocha said the stabbings happened Sunday night in the volatile city of Jos. He said soldiers dispersed rioters who gathered in a predominantly Christian neighborhood Monday morning to protest the killings.
Sporadic violence recently resumed after months of relative calm in Jos and surrounding areas, which are heavily policed. A clash there left five dead in July after a Muslim locksmith was found dead in a Christian neighborhood.
Human Rights Watch says at least 1,000 people were killed in the area in 2010 and another 200 died at the turn of the year. Violence there cuts across religious lines, but has roots in political, economic and ethnic strife.
Also on Monday, a 25-year-old man was killed by guards as he attempted to drive a sedan loaded with gas cylinders, cans of gasoline and gunpowder into a police headquarters, said Borno state police commissioner Simieone Midenda.
The failed attack in the country's troubled northeast came during a drive to recruit 1,500 new officers for the region.
Police blamed Boko Haram, a group whose name means "Western education is sacrilege" in the local Hausa language. The group claimed responsibility for a bombing at national police headquarters in Abuja that killed at least two people in June.
Associated Press writer Njadvara Musa contributed to this report from Maiduguri, Nigeria.