Monguno, a town of about 100,000 people in northeast Nigeria, is about a 135-kilometer (85-mile) drive from Maiduguri, a city of more than 600,000. Both cities are tucked into the corner of the country, near the borders with Chad and Cameroon.
Babagana Musa, a Monguno resident who fled to Maiduguri, said, "Several trucks carrying soldiers drove into Maiduguri. We learned the town (Monguno) has been taken over by Boko Haram."
Monguno, with its huge military barracks, has a strategic importance in that it acts as a buffer to keep Boko Haram from advancing towards Maiduguri. Its fall means Boko Haram is in good position to advance on Maiduguri, which has been its goal for months.
Boko Haram had been confined to the fishing town of Baga since its fighters seized it January 3, hesitant to move south towards Maiduguri because of the military presence in Monguno.
The Islamists attacked the nearby village of Jintilo around 5 a.m. and were engaged in a gunbattle with troops stationed there. The village is about 5 kilometers (3 miles) from the center of Maiduguri, the capital of Borno state.
The fighting in Jintilo forced residents to evacuate their homes and flee into the city, while military authorities imposed a round-the-clock curfew to prevent infiltration by the militants.
"All the residents of neighborhoods near Jintilo have fled into the city due to the ongoing battle between troops and Boko Haram gunmen who want to enter the city," said Modu Zannari, who lives nearby.
"Boko Haram gunmen in their hundreds attacked Jintilo around 5 a.m., just before the morning prayers, but soldiers stationed there fought back," Zannari said
"Since 5 a.m. all we hear are cracking of guns and booming explosions coming from the direction of Jintilo," said Babakaka Said, a resident of another neighborhood near the scene of the fighting.
"There have been radio announcements of indefinite curfew in the city and we have all been asked to remain indoors," said Adam Kolo, who lives in the heart of the city.
Hundreds of troop reinforcements deployed in Jintilo and military jets carried out aerial bombardment of Boko Haram positions, said a member of a civilian vigilante group fighting Boko Haram alongside troops.
The attack came a day after President Goodluck Jonathan made a campaign stop in Maiduguri ahead of the February 14 presidential election. He has promised to end the Boko Haram insurgency if re-elected.
Boko Haram is also believed to be responsible for a cross-border raid into neighboring Cameroon where three were killed and as many as 80 people were abducted- many of them children.