A mob in northeastern Nigeria has beaten a woman to death and burnt her body over suspicion she was planning to carry out a suicide bombing, police and witnesses have said.

Witnesses said the victim and a second woman had refused to be searched at the entrance of the largest market in the city of Bauchi on Sunday morning.

Bauchi state police spokesman Haruna Mohammed described the slain woman as the victim of "mob action carried out by an irate crowd". 

It seemed doubtful the woman was actually a bomber as she did not detonate any explosives when she was attacked, Mohammed said.  

He said police had deployed to the scene to disperse the mob but the woman died before officers could rescue her. None of the attackers were arrested, he said.

However, the second woman who allegedly refused to be searched was arrested, the Associated Press reported. The news agency said both women were teenagers.

Vegetable vendor Mohd Adamu told the AP that when the women refused to be screened, people overpowered one girl and discovered she had two bottles strapped to her body. They clubbed her to death, put a tyre doused in fuel over her head and set it on fire, he said.

A spate of suicide bombings has been blamed on Nigeria's Boko Haram group, which wants to enforce strict Islamic law in the north. 

Recently some girls as young as 10 years old have been used to carry explosives that detonated in busy markets and bus stations. It is unclear whether the girls detonated explosives themselves or whether the bombs were controlled remotely.

About 10,000 people died in Nigeria from Boko Haram's violence last year, compared to 2,000 in the first four years of the group's armed campaign, according to the US Council on Foreign Relations. About 1.5 million people have been driven from their homes.