This demonstrated their ability to attack civilians hours after a bomb blast killed 118 people in the central city of Jos.
In one raid, militants opened fire on Alagarno village and razed several houses to the ground, killing 17 people overnight, a source at police headquarters told Reuters. The attack was barely 30 km (20 miles) from Chibok, from where Boko Haram Islamists abducted more than 200 schoolgirls last month.
In the other, men on motorbikes attacked the nearby village of Shawa, killing nine people on Monday.
There was no immediate claim of responsibility, but Boko Haram has either claimed or been blamed for scores of similar such attacks in this part of Borno state, near the hilly border with Cameroon.
Violence by Boko Haram, an Islamist militant group fighting for the past five years to carve an Islamic state out of religiously-mixed Nigeria, has surged in the past two months.
Bomb attacks are growing more frequent and sophisticated, including two on the capital last month, and massacres of helpless villagers are an almost daily occurrence.
The Jos attack, if it was Boko Haram, showed the group's growing reach as it spreads outwards from its traditional heartland in the northeast. Though it was not the first attack in Jos, it was by far the deadliest.