Unidentified gunmen abducted Numal Boruah, 55, the manager of Timon Habi tea estate, from his bungalow under Borhat police station in Upper Assam’s Charaideo district on Tuesday night.

This is the third incident of abduction in less than a fortnight, amid reports of youths joining Ulfa (I). The area is around 85km west of Tinsukia and 430km east of Guwahati.

The abduction comes at a time when Ulfa (Independent) has claimed involvement in the abduction of the caretaker of a stone-crushing plant, Apurba Kakoti, from Jagun in Tinsukia district.

Purna Borah, brother of the owner of the stone crusher plant, told The Telegraph that he received a call around 9am. “The caller identified himself as Nayan Medhi from Ulfa (I) and informed me that Kakoti is with them and is fine.”

The outfit had earlier demanded a ransom of Rs 3 crore from Sati tea estate to release its storekeeper Debabrata Deb. He was released a few days later.

On Tuesday night, a trader at North Borbil in Karbi Anglong district was kidnapped at gunpoint by three men when he was returning home, police said.

A high-level meeting had been chaired before the abductions this month by the special secretary, ministry of home affairs (internal security), Rina Mitra, at the Indian army's Dao Division headquarters in Dinjan, in which top army and CRPF officials and police officials from Assam, Arunachal Pradesh and Nagaland took part, besides senior officials of the Intelligence Bureau, to review internal security and better coordination among forces involved in counter-insurgency operations.

Additional superintendent of Charaideo police Lamhao Doungel told The Telegraph, “Four men came and abducted the garden manager from his bungalow around 7.30pm on Tuesday. We suspect the hand of Ulfa (I) and have launched search operations and alerted security forces in Longding, Arunachal Pradesh. We have sought the help of Longding police.”

Charaideo in Assam has a porous border with Arunachal’s Longding district. According to intelligence sources, Ulfa (I) has camps in Myanmar and they use Longding as a transit route.

The abducted man’s wife, Nonima Boruah, appealed to Ulfa (I) chief Paresh Barua to release her husband. “The abductors identified themselves as Ulfa (I) members. Hence, I beg Paresh Barua dangoria to return my husband. Mur lora eta, lora thu horu hoi aase. Tekhet ne thakile mur aaru kaam nai prithavit (We have a small kid. Without my husband around, my life will not he worth living),” she told reporters while weeping.

According to sources, out of the four men, three were armed and in camouflage.

“They told Boruah’s wife that the garden owner’s behaviour was not good. They said they would settle with him and release her husband. They warned her not to call the police before 8am on Wednesday. She informed the police after 12 hours,” a source added.

There has been a spurt of militant activities in Upper Assam after the killing of five persons at Dhola in Tinsukia district. Ulfa (I) denied any role in the killings.