Hanoi  - Vietnamese police have arrested a woman who allegedly tried to kill the baby of her husband and another woman by driving a sewing needle into his brain, a police official said Thursday.

Hanoi resident Nguyen Thi Kim Duan, 35, was officially arrested Wednesday in the province of Thai Nguyen, after being detained informally since November 6, said district police chief Diep Van Cao.

Cao said Duan arrived in Thai Nguyen on November 6 to visit Nguyen Thi Thanh. Thanh had reportedly begun an affair with Duan's husband, a construction worker, the previous year.

According to Vietnamese press accounts, Duan was aware of the affair and the child resulting from it, then 30 days old. She told Thanh she would like to treat the child as her own.

Duan asked if she could hold the child for a while, then reportedly carried the baby out of sight and forced a 10-centimetre sewing needle into his head.

The baby's mother later discovered the end of the needle still protruding from the crying baby's head, and called for help. Her neighbours held Duan until police arrived.

Doctors at Thai Nguyen General Hospital operated and removed the needle but said they were unsure how severely the episode might affect the child's future mental development.

Police chief Cao said Duan had confessed to the crime, which she said was prompted by jealousy.

If convicted of attempted murder, Duan faces life in prison. (dpa)