A Nigerian police official says seven people were killed and three injured when their bus ran over a homemade bomb planted by suspected Islamic extremists in a northeastern village.

Borno state police commissioner Lawan Tanko said said Friday's blast occurred in Kuthra village and the injured are receiving treatment in the main town of Gwoza.

Gwoza is about 90 kilometers (60 miles) from Kawuri, a village where gunmen also believed to be extremists attacked the market last Sunday with guns and explosives, killing at least 85 people. They also left behind improvised explosive devices. Another Sunday attack at a church in Adamawa state, using explosives and guns, killed at least 45 people.

Thousands have been killed during the four-year insurgency by Boko Haram extremists who want to impose Shariah law.