Boko Haram gunmen dressed in military uniform on Sunday killed 19 people near the Nigerian border with Cameroon in the restive northeast where the Islamists have carried out deadly attacks, residents and a survivor said.
Nigerian troops patrol the streets of the remote northeast town of Baga on April 30, 2013
The motorcycle-riding gunmen armed with Kalashnikovs blocked the highway near the town of Logumani, 30 kilometres (19 miles) from the border, shooting and hacking to death 19 motorists and burning three trucks, they said.
"We have recovered 19 dead bodies from the scene of the attack by Boko Haram gunmen," Musa Abur, leader of a civilian vigilante group in the area told AFP.
"Five of the victims, who included two truck drivers and their assistants, were shot dead while the rest were slaughtered," he said.
He said the gunmen had attacked the border town of Gamboru Ngala near Logumani late Friday but were repelled by soldiers and local vigilantes.
A passenger who survived the attack gave a similar account.
"We were asked to get out of our vehicles and lie face down by nine men dressed as soldiers who blocked the road around 5:00 am," the man who gave his name as Buba told AFP.
"They shot dead five people and went about slaughtering 14 others before someone called them on the phone that soldiers were heading their way," he said.
"They abandoned the rest of us and sped into the bush on their motorcycles," added Buba, who was shot in the leg.
He said the attack bore the hallmarks of Boko Haram.
"We knew they were Boko Haram from their appearance. Soldiers don't wear beards but some of the gunmen were bearded," he said.
"Everyone in this area knows Boko Haram is on the prowl, raiding villages and attacking vehicles. It has become a common occurrence."
The military authorities in the region could not be immediately reached for comment.
The phone network has been switched off in much of the northeast since emergency measures were declared mid-May at the start of a military offensive against the insurgents.
Defence officials say the offensive against Boko Haram has decimated the group and scattered its fighters across remote parts of the northeast, the insurgents' traditional stronghold.
Military authorities have encouraged the formation of vigilante groups to help flush out the Islamists.
But Boko Haram has stepped up deadly attacks on civilians and schools in reprisals against vigilantes cooperating with the military.
The group says it is fighting to create an Islamic state in Nigeria's mainly Muslim north, but it is believed to be made up of different factions with varying aims.
Boko Haram has attacked churches, mosques, newspaper offices, the security forces, politicians and a UN building, among other targets.
Violence by the group is estimated to have cost more than 3,600 lives, including killings by the security forces.
Nigeria is Africa's most populous country and top oil producer, roughly divided between a mainly Muslim north and predominantly Christian south.