Story highlights The girl was riding her bicycle on the way to the metro station with her mother

A 33-year-old man surnamed Wang has been apprehended

The suspect has a history of mental illness, Taiwanese state media says

(CNN) A 4-year-old girl was beheaded in Taiwan in what appears to have been a random knife attack, state media said.

On Monday morning, a 33-year-old man attacked the girl with a cleaver in full view of her mother as they were on their way to a metro station in Taipei, the island's capital, the official Central News Agency, or CNA, said

The mother of the slain child said her daughter had been riding her bike about a meter away from her when it became stuck.

She saw the man approaching and at first thought he was going to help her daughter but he drew his knife and decapitated her.

"At first I thought he was going to lift up the bike to help my daughter. When I walked over to tell him that it's OK, I saw both of them fall on the ground, and the suspect was wielding the knife and cutting my daughter," she said.

Read More