Patna, Mar 17 (IANS): After disappearance of a leading doctor, a Class 6 student, the a son of a government teacher, was kidnapped by unidentified men and Rs 40 lakh ransom demanded for his release, police said on Friday.

"The kidnappers have demanded ransom using the mobile phone of the victim. An FIR has been registered in this regard in Bihta police station. The victim is identified as Tushar Kumar. He had disappeared Thursday evening," Bihta police station SHO Sanovar Khan said.

The police said that the kidnappers used the boy's mobile phone to demand the ransom. They have also sent the text message on Whatsapp and then switched off the phone. The police sources have said that it is difficult to trace the location of the accused.

"My son returned home from the coaching classes and went to the market for some work. When he did not return late in the evening, we started searching for him. We eventually informed the Bihta police about the incident," said Raj Kishore Pandit, father of the victim.

The kidnapper threatened him not to reveal the incident to anyone, he said. They have also said that they are observing the activities of the family.

"The kidnappers threatened us not to reveal the incident to police. They also informed me that Tushar is in an unconscious stage and if the ransom amount is not paid, they will kill him," he said.