Nigerian troops have retaken a major border town and killed scores of Boko Haram fighters, Nigeria's military says.
Witnesses also report that the Islamic extremists have killed scores in attacks on other villages.
Defence Ministry spokesman Major General Chris Olukolade said troops seized back the garrison town of Baga, on Lake Chad and the border with Cameroon, after a fighter jet bombarded the area and soldiers advanced on booby-trapped roads by dismantling some 1,500 land mines.
"Many of the terrorists died while an unknown but substantial number of them fled with various degrees of injury," Olukolade said.
Many insurgents drowned in trying to escape as soldiers stormed into Baga early on Friday, he added.
The victory, which the AP was unable to verify independently, comes amid a major multinational push to halt the spreading Islamic uprising by Nigeria's home-grown extremist group, which has been attacking neighbouring Chad, Cameroon and Niger.
In the latest Boko Haram violence involving Niger, a military official said on Saturday that seven soldiers were killed in an overnight attack on the island of Karamga in Lake Chad.
Colonel Salaou Barmou said 14 Boko Haram assailants were also killed in the fighting on Friday night.
In a major turnaround after months of gains by Boko Haram, military from Nigeria and Chad have reported retaking at least a dozen towns in recent weeks that had been in extremist hands for months.
Boko Haram leader Abubakar Shekau this week warned he will disrupt March 28 presidential elections that are shaping up to be the most closely contested vote in the history of Africa's most populous nation and its biggest oil producer. Boko Haram wants to install an Islamic caliphate and says democracy is a corrupt Western concept.
Earlier this week, residents and local officials said suspected Boko Haram fighters killed at least 34 and injured several others in attacks on villages near Konduga and Chibok, the town where in April last year Boko Haram kidnapped nearly 300 schoolgirls in northeastern Borno state. Dozens escaped independently but 219 are still missing.
International concern has increased along with the number of fatalities, estimated at some 10,000 in the past year with about 1.5 million people driven from their homes, according to the US Council on Foreign Relations.
