BAUCHI, Nigeria, March 1 (UPI) — A Nigerian mob beat a teenage girl to death on Sunday after suspecting her of being a suicide bomber, police and witnesses say.

The incident comes after a series of suicide bomb attacks in the country by young female perpetrators. Militant group Boko Haram, which since 2009 has waged war seeking an Islamic state in Nigeria, has been blamed for the attacks.

Witnesses said the girl, who may have been accompanied by a female or male escort, refused to be screened with a metal detector at the entrance of a market in the northeastern city of Bauchi. After the girl raised her veil, the crowd saw two bottles attached to her waist and attacked, according to witnesses.

The mob then put a petrol-covered tire over the badly beaten girl and set her on fire. She was dead when police arrived.

Authorities said she had no explosives on her but also noted that she might have been performing reconnaissance for a future attack.

Attacks by female bombers have increased in recent months. Last week a suicide bomber described by witnesses as a young female killed herself and five other people after detonating at a market checkpoint in Potiskum — where on Jan. 11 the same mobile phone market was struck by two blasts that witnesses said were detonated by two preteen girls.

On Feb. 15 a female suicide bomber killed seven people and injured over 30 at a bus station in Damaturu. Four days earlier a female suicide bomber was shot to death before detonating in Diffa.

Boko Haram gained international infamy when it kidnapped over 200 schoolgirls from the village of Chibok in April 2014. Experts have speculated the group might be using abducted children to conduct the recent series of suicide bombings.

In the face of increased attacks by Boko Haram, Nigeria was forced to delay national elections scheduled for Feb. 14. The new date is March 28.