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 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.
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.