HILLA, Iraq (AFP) – A Baghdad police lieutenant kidnapped his wealthy neighbour's 10-year-old son, killed him and then sought 160,000 dollars before being snared when his phone calls were traced, police said on Tuesday.

The crime occurred in Mahawil, a town 80 kilometres (50 miles) south of Baghdad, in Babil province.

"We have arrested him and he has confessed to the crime," a police official in Hilla, the provincial capital, told AFP.

The killer, named as Lieutenant Haidar Atlas, worked in Baghdad but decided to snatch the son of Khudair Abdul Zahra, a food trader and neighbour in Mahawil, his home town.

"We caught him on Monday, the corpse was discovered and he has confessed to the crime," the official said, asking not to be named.

Atlas was discovered after calls from his mobile telephone to demand ransom money were traced back to him by investigators.

"He asked for 160,000 dollars but he had killed and buried the child immediately after the kidnap," the police official added.

The kidnapping of children has been on the rise in Iraq in recent months, most notably in the oil-rich city and province of Kirkuk, where criminal gangs have targeted wealthy families.

"Since September, the kidnapping of children has increased," Kirkuk's deputy police chief General Turhan Yussef said on Wednesday, noting "at least 10 cases" were known about but he suspected many more.

"Two were freed by our forces, one child was released after payment of a ransom, three others were after direct negotiations between the parents and the abductors and four, including two girls, are still being held," he said.