In the first attack, which happened at noon on Thursday, jihadists on motorcycles attacked people beside a reservoir in Maichulmuri village, just outside Borno state capital Maiduguri.
"We have so far recovered nine dead bodies."
More were feared killed as the gunmen chased people as they fled into the bush, said villager Modu Alhaji Sheriff, who gave a similar death toll.
The area has been repeatedly attacked by fighters loyal to Boko Haram leader Abubakar Shekau.
The militants stormed into Shuwa village around dusk, killing three people including a policeman, before soldiers fought them back, residents said.
"Three people died in the attack on Shuwa," local resident Paul Waramulu said.
Leaving that village in flames, the fighters stopped off at the nearby village of Kirchina -- torching that too -- and then drove to Kuda village.
"They killed two people," said Kuda resident Simon Damina.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)