The Nigerian army says it has retaken the north-eastern town of Gwoza, believed to be the headquarters of militant Islamist group Boko Haram.
"Several terrorists died while many are captured," a tweet from the defences forces said.
Mopping-up operations are ongoing in and around the town, the military said.
News of the recapture comes a day before presidential elections, which were postponed by six weeks because of the offensive against Boko Haram.
Thousands of people have been killed since 2009, when the group began its insurgency to create an Islamic state.
Since a regional force began helping Nigeria take on the insurgents this year, many towns have been retaken.
The most recent military briefing said that only three districts, including Gwoza, remained under Boko Haram's control, down from 14.
After his fighters captured Gwoza in August 2014, the Boko Haram leader declared a caliphate in areas under his control.
"Troops this morning captured Gwoza destroying the Headquarters of the Terrorists self styled Caliphate," a tweet from Nigerian armed forces said.