CHANGCHUN - Authorities on Thursday approved the arrest of a man who allegedly murdered a baby on Monday in northeast China's Jilin Province.

At 6 p.m., the Changchun Municipal People's Procuratorate formally approved the arrest of Zhou Xijun, who turned himself in to police on Tuesday, confessing to stealing an SUV and strangling its two-month-old passenger.

The boy's parents identified the body of their child on Wednesday.

Zhou, 48, told police he found the baby in the back seat after stealing the car and driving it onto a highway. He then strangled the infant and buried him in the snow.

Authorities of the Jilin Public Security Department denied online rumors that Zhou's motive was revenge against the baby's family, saying the murder was a spontaneous act.

The car belonged to a local resident surnamed Xu.

Xu parked in front of the supermarket he runs and entered the store to turn on a stove, leaving his son in the back seat without shutting off the car's engine.

He came out of the supermarket minutes later only to find that his car had been stolen with the baby still inside. He called the police immediately.

In a telephone interview with Xinhua, Xu said that he did not know Zhou.

After a detailed investigation, local police confirmed Zhou as the suspect of the crime.

Online rumors had said that Zhou confessed to police of the crimes which had actually been committed by his son, as some netizens said the suspect was in his 30s and about 180cm tall. It is unknown if Zhou has a son.

More than 8,000 police were dispatched to hunt for the thief after the report of the missing baby in the car. Hundreds of volunteers also joined in the search across Jilin.

Zhou confessed that he parked the car on the roadside and choked the baby about an hour after he stole the car. He then abandoned the baby's clothes and the car in the nearby city of Gongzhuling.

Many Chinese Internet users have discussed the tragedy and mourned the baby online.

Local judicial authorities are treating the incident as a major criminal case and are conducting a further investigation.

The case in under further investigation.