Residents in Bulabulin-Ngabura village said Boko Haram members who staged the highway attack early Thursday also kidnapped a family of five who were traveling to their country home in Biu for the weekend.
Cab driver Musa Lado told The Associated Press that dozens of insurgents staged the attack, which killed a Borno state government adviser.
Another cab driver said "we could not move along the highway for several hours because of the attack. And by the time we were told the road was safe to continue our journey, we saw corpses of nine persons including that of an adviser in the Borno state government." He spoke on condition of anonymity out of fear for his safety.
The driver also said a man, his wife and three children were kidnapped from their car along the highway, and he helped get the vehicle to Biu.
Since 2010, more than 1,700 people have been killed in attacks by Boko Haram, whose name means "Western education is forbidden."
There has been a rash of attacks by suspected sect members in northeast Nigeria recently, after young vigilantes formed the Civilian Joint Task Force in June as a backlash against Boko Haram. The Civilian-JTF group has taken over in the search for the insurgents in many towns in the north, and most Boko Haram members have since relocated to the surrounding bushes. The vigilante force claims credit for thousands of arrests in Maiduguri and many killings.
Many residents welcome the vigilantes and credited them for some initial relative peace. Others find their existence troubling and worry that they may carry out human rights abuses.
Nigeria's Chief of Army Staff Lt. General Azubuike Ihejerika on Friday commended the Civilian-JTF group for helping the government catch Islamic sect members in northeast Borno state.
"I wish to commend the youth volunteers for their support in fighting the insurgency," Ihejerika said in the first endorsement of the group by a high ranking military officer.
Ihejerika was in Maiduguri to oversee the deployment of troops and equipment for the newly established 7th Division of the Nigerian army. The new division, once fully established, would bring an end to the mandate for the Civilian-JTF, which has had military backing when it goes out on missions.
The vigilante group members have also become targets.
On Aug. 30, suspected Islamic sect members ambushed and killed at least 24 members of the Civilian-JTF who were on a mission to find and fight the sect near Monguno town, 160 kilometers (100 miles) from the city of Maiduguri. Those who returned from the attack said 36 other vigilantes were missing.
Earlier that week, two attacks killed at least 20 members of the Civilian-JTF in Damasak, where six members were shot while sleeping, and in Barma, where attackers disguised in military uniforms slit the throats of young men.