"I'm seeing people carrying bloody bodies," he said. "There are parts of bodies littering the street."
Mechanic Yahaya Adamu said he was on his way home when he heard the blasts, two minutes apart. "There's black smoke everywhere now. I'm running home to see if my family is safe."
The police commissioner didn't immediately answer his phone to confirm the reports.
It was the first attack in months in Maiduguri, capital of Borno state and the headquarters of a military force tasked with suppressing the four-year-old Islamic uprising that has killed thousands.
More than 300 people were killed in February alone in attacks increasing in frequency and deadliness, all in the neighboring states of Yobe and Adamawa.
There is growing anger at the military's apparent inability to halt the attacks, with soldiers reportedly abandoning checkpoints in two recent attacks that killed nearly 100 people, including 59 students, because they are outnumbered and outgunned.
That anger will be fueled by reports that a military fighter jet targeting extremist hideouts bombed a village in Yobe state and killed at least 20 civilians on Friday, according to survivors.
They said the airstrike hit Daglun, a village near Nigeria's border with Cameroon and killed mainly elderly people because most residents had fled recent violence and rumors that the military is about to mount more attacks.
Military spokesman Capt. Jafaru Nuru of the 23rd Armored Brigade operating in Yobe state said he was unaware that any airstrike had killed civilians.
An elderly resident of Daglun said he was sitting under a tree when he saw bombs dropping from a military aircraft. A nurse at the local hospital said it received many dead and wounded. A community leader said 20 people died and 25 were wounded.
All requested anonymity citing fear of military reprisals.
Jets have been bombing the area for weeks in the latest offensive to suppress an Islamic insurgency in Africa's most populous nation of about 170 million people. The country is almost equally divided between the mainly Muslim north and predominantly Christian south. Boko Haram is fighting to impose Islamic law across the entirety of Nigeria, Africa's biggest oil producer.
Three northeastern states covering one-sixth of Nigeria are under a 9-month-old state of emergency. The military's offensive has featured previous airstrike mistakes.
In January, a jet dropped bombs near a federal senator, who was traveling in a convoy being escorted by soldiers and police. No one was hurt. The military called the bombing "an operational blunder" though the convoy was led by a military vehicle and had a police van in the rear.