LAGOS, Nigeria -- A series of weekend attacks have left at least eight people dead as Nigeria's security situation continues to deteriorate amid a rising Islamist insurgency, authorities said Monday.
Motorcycle-mounted gunmen killed three police officers at a checkpoint in Nigeria's troubled northeast, Adamawa police spokeswoman Altine Daneil said Monday. She said two officers died on the spot and another died in a hospital after Sunday's attack in a town close to Adamawa's border with Borno State, the spiritual home of a radical sect known as Boko Haram.
Daneil said a fourth officer is in the hospital.
She said cans that appeared to be homemade explosives had been found in the area.
Daneil said it was too early to say the police suspected any specific group, but Boko Haram has carried out similar drive-by shootings in the past.
At least five other people died in weekend attacks across Nigeria.
Boko Haram has claimed responsibility for one of those attacks, which hit a major church in central Nigeria Sunday morning and killed three people.
The group has launched increasingly bloody attacks across Nigeria, including ones targeting churches and police.
Boko Haram, whose name means "Western education is sacrilege" in the local Hausa language, is carrying out increasingly sophisticated and bloody attacks in its campaign to implement strict Shariah law and avenge Muslim killings in Nigeria, a multiethnic nation of more than 160 million people.
Authorities said Saturday that suspected sect gunmen killed two police officers in separate attacks in Kaduna and Maiduguri, areas previously targeted by the sect.
In Gombe state, an unexploded bomb from a Friday Boko Haram attack that had killed 12 people detonated Saturday morning outside a police building, though it was not immediately clear if anyone was injured.
Also Sunday, police in Bauchi state said they stopped an attack on a church, though they said the seven people arrested were Christians who were embroiled in an internal dispute with the church.
Meanwhile, gunmen attacked two villages in rural Kaduna state late Sunday night, leaving two young people dead and another badly injured, said southern Kaduna community leader Florence Aya.
An Associated Press reporter contributed from Kaduna, Nigeria.