Kano, Nigeria (CNN) -- A suicide bomber killed at least six people in the northeastern Nigerian city of Maiduguri on Monday, while Boko Haram militants attacked the town of Damaturu to the west but were driven out after a 10-hour battle.
The sector commander for Maiduguri's civilian task force told CNN a female bomber had carried out the attack on the city's market at 11:00 a.m.
At least six people had died and the toll was expected to rise, Cmdr. Abba Aji Kalli said. More than 20 people had been taken to hospitals, many in critical condition, he said.
Police gave a slightly different account, saying two female bombers had targeted the main gate of the market, killing five.
A source at the Maiduguri General Hospital said 48 injured had been taken to the hospital from the scene of the attack.
Last week, another suicide attack in Maiduguri, the capital of Borno state, killed at least 78 people.
Meanwhile, battle sounds roared in Damaturu in neighboring Yobe state early Monday as Islamist Boko Haram fighters poured in, an eyewitness said.
"I was in bed around 4:40 a.m., when I was jolted out of sleep with huge explosions and sounds of gunfire," said resident Buka Girema.
Girema fled with his family into nearby brush land. Neighbors have fled their homes as well, he said.
"After some phone calls, I realized Boko Haram gunmen were on the attack. They came in several trucks and vans," he said. They set fire to a police checkpoint, he said.
Militants pushed toward the center of town, and the sound of gunfire spread to compounds that house government workers, residents said.
A nurse working in the town spoke to CNN by telephone as gunshots rang out in the background.
She said she was hiding in her home, and then concluded quietly, "They have entered my house. Please pray for me," before hanging up the phone.
'Heinous and barbaric'
The attack on Damaturu ended in midafternoon. Yobe state spokesman Mohammed Hassan said the Boko Haram fighters were forced out of the town.
"The insurgents were not able to come in full force. They were not able to operate as they wanted. The authorities pushed them out. Many civilians also helped," Hassan said.
Yobe Gov. Ibrahim Gaidam condemned the attack on Damaturu as "heinous and barbaric" and praised security forces for their efforts repelling the militants.
"His Excellency the governor has also been told that the security effort is still ongoing. Security agents will continue to track and pursue any remnants of the attackers who might still be hiding in town.
"The governor urges people in Damaturu and all across our State to continue to remain vigilant and pray to Almighty Allah for His intervention," state spokesman Abdullahi Bego said in a statement.
Campaign of violence
Boko Haram has terrorized northern Nigeria regularly since 2009, attacking police, schools, churches and civilians and bombing government buildings.
On Friday, two suicide bombers and gunmen attacked a Muslim congregation during prayers in the central mosque in northern Nigeria's largest city, Kano, officials said. A third bomb exploded outside the mosque.
Officials said more than 100 people were killed in the attack.
It came two weeks after the emir of Kano, Muhammad Sanusi II, one of Nigeria's most influential monarchs, called for self-defense, urging people to procure arms and fight Boko Haram, which has a significant presence in the area.
The emir made the call at the same mosque where Friday's attack occurred.
In April, Boko Haram militants drew international condemnation when they kidnapped more than 200 schoolgirls, many of whom they later said they sold into slavery.
At least 5,000 people have died at Boko Haram's hands, according to a U.S. Congressional Research Service report, making it one of the world's deadliest terrorist organizations.
Journalists Aminu Abubakar and Hassan John reported from Nigeria; CNN's Ben Brumfield wrote and reported from Atlanta. CNN's Nima Elbagir, Lillian Leposo, Kay Guerrero, Tina Burnside and Susannah Cullinane contributed to this report.