Abuja: Nigeria`s military on Friday announced that troops had retaken the town of Gwoza from Boko Haram, from which the group declared their caliphate last year.
"Troops this morning captured Gwoza destroying the Headquarters of the Terrorists self-styled Caliphate," Defence Headquarters in Abuja said on Twitter.
"Several terrorists died while many are captured. Mopping up of entire Gwoza and her suburbs is ongoing," it added in a separate message.
Earlier this month, residents who fled the town in Borno state told AFP that militants had been massing in Gwoza and killing local people who were unable to flee.
That led to speculation that the group, which has been pushed out of a number of towns in three northeast states in recent weeks, was preparing for a final assault.
Boko Haram leader Abubakar Shekau declared on August 24 last year that Gwoza was "part of the Islamic caliphate", adding to speculation the militants were imitating the Islamic State group.Shekau had the previous month praised IS leader Abu Bakr al-Baghdadi but stopped short of pledging allegiance. He has since formally allied himself to the group in Syria and Iraq.
Nigeria`s national security spokesman Mike Omeri said last week that troops had begun the "final onslaught" against Boko Haram, saying Gwoza was one of three areas yet to be retaken.
A four-nation coalition of Nigeria, Niger, Chad and Cameroon has claimed a number of successes since the turn of the year to end the insurgency which has claimed more than 13,000 lives since 2009.
The ongoing operation was cited as a reason to delay Nigeria`s general election on February 14 to this Saturday, as soldiers would not be able to provide security nationwide.
In a televised address broadcast on Friday, President Goodluck Jonathan hailed troops for having "successfully stemmed the seizure of Nigerian territories".
"I heartily commend the very courageous men and women of our Armed Forces for the immense sacrifices which they continue to make in defending the nation and protecting its citizens," he added.
But Chad`s President Idriss Deby accused Nigeria of failing to cooperate with the regional coalition battling the jihadists, saying there had been zero contact between their armies.
"The whole world is asking why the Nigerian army, which is a big army... is not in a position to stand up to untrained kids armed with Kalashnikovs," Deby told French magazine Le Point, in an interview published this week.