Doomdooma/Tinsukia: Devendra Kumar Sinha, an engineer who was abducted on October 8 by suspected militants from Bordumsa in Arunachal Pradesh's Changlang district, was released on Sunday night.

Intelligence sources today said the NSCN (Isak-Muivah) was behind the kidnapping.

"Four armed men came in a red car and called the engineer out of his home. When the engineer did not come out, two men went inside, hit him with the butt of the rifle and forcibly took him in the car," the source said quoting Sinha, who recounted his ordeal at Bordumsa police station.

Sources said the armed militants drove him to Newton Basti under Mhow police station from where he was made to walk over an hour until they reached a camp.

"Five militants were already there and three more joined them two days later," a source said. "On Sunday, the rebels told him he would be released. He was dropped at an unknown location and asked to walk straight till he reached Kharsang," a source said. "It is still not clear how much ransom was paid but reports suggest negotiations took place with higher-level police officers," he added.

Sinha, who hails from Bihar's Nalanda district, had called his friend from an unknown number and said he had been kidnapped. He said the abductors had demanded Rs 1.5 crore for his release. Sinha is a resident engineer of National Highways and Infrastructure Development Corporation Ltd under the ministry of road transport and highways.

Bordumsa is 55km from Doomdooma and 102km from Tinsukia.

On September 28, during Durga Puja, Sailyo Dahotia, the manager of Dihingia tea estate in Tinsukia district, was abducted by militants from the estate in Kathalguri near the Assam-Arunachal Pradesh border.

The outfit had demanded Rs 20 lakh from the proprietor of the tea estate, Rajib Phukan, to free Dahotia. He was released on October 5.