By Camillus Eboh
ABUJA (Reuters) - Nigerian ground forces backed by air strikes are fighting to reclaim Baga from Islamist militant group Boko Haram which seized the northeastern town and a nearby military base at the weekend, a government spokesman said on Friday.
"Since the first attack last weekend on Baga, security forces have been actively pursuing the militants," Mike Omeri said in a statement. "Security forces have responded rapidly, and have deployed significant military assets and conducted air strikes."
At least 100 people were killed when Boko Haram attacked Baga last weekend, according to the district head.
Witnesses who escaped to neighboring towns and Borno state capital Maiduguri said the insurgents had razed many buildings and homes and killed dozens of civilians in subsequent raids this week.
Soldiers had fled the area after the nearby army base, which is the headquarters of a multinational force comprising troops from Chad, Niger and Cameroon, by Lake Chad was overrun.
Some 300 km (200 miles) away, on Friday evening, gunfire, explosions and heavy artillery fire were heard on the outskirts of Yobe state capital Damaturu.
"We can hear the artillery fire and then the ground shaking," a Reuters cameraman said.
Boko Haram has been waging a 5-year insurgency to carve out an Islamic state in northeastern Nigeria.
Government spokesman Omeri said the National Emergency Management Agency, working with the Red Cross, was providing humanitarian assistance to 2,000 people who had fled Baga.
Some 2,000 more people crossed the border to Chad over the last week, prompting the country to call for international aid. Cameroon has also appealed for aid to help fight the militants.