A witness says stray bullets from an army shootout wounded a woman and killed a baby strapped to her back in Nigeria's northeast.

The witness, who spoke on condition of anonymity out of fear for his safety, said he saw soldiers shooting after an explosion hit Maiduguri city Tuesday.

It remains unclear if others were shooting back.

Army spokesman Lt. Col. Sagir Musa said he was unaware of the shootings of the woman and child.

He said soldiers shot dead a man who was pushing a wheelbarrow that contained explosives. He added that nobody died in the blast.

Musa blamed the attack on a radical Islamist sect known as Boko Haram, which is held responsible for more than 660 deaths this year, according to an Associated Press count.