Two students of a reputed school in Delhi were murdered after being kidnapped for ransom by a four-member gang, raising fresh questions over children's safety in Delhi after the Nithari killings nearby.

The bodies of Sarvodaya Senior Secondary Model School students Chetan Swaroop (14) and Sahil Goyal (13), who were abducted on Monday, were found with their throats slit on Monday night in a wooded area in north-east Delhi, police said on Tuesday.

The bodies were found after police arrested the abductors, one of them known to the children, by tracking a telephone call made by them to the families demanding Rs 4 lakh as ransom for their safe release.

The arrested have been identified as Monu, whose brother works in the shop of Sahil's grandfather, Mohammed Nadeem, Shakeel and Vinod, who was the driver of the three-wheeler used for kidnapping the teenaged cousins.

According to police, Monu offered a lift to the children when they were returning from school on Monday afternoon and since Sahil knew him, they accepted the offer.

The assailants then took them to a ridge in New Usmanpur locality, killed them and dumped the bodies there.

The families of the children, residents of Karaval Nagar in north-east Delhi, had in the evening approached the police after the two did not return from school, triggering a major hunt to trace them.

The kidnappers contacted the children's uncle Vikas Goel from a public call booth at around 7.45 pm and demanded Rs 4 lakh, police said.

The call was immediately traced by police and they were arrested. During interrogation, the four told police that they kidnapped the children for money and killed them to erase all evidence.