"Rescue teams from the Army, Indo-Tibetan Border Police along with state police were trekking through the jungle and hill areas between Yupia and Hoj Telam in Papum Pare district to locate the missing chopper," Sandeep Goel, the police chief of Arunachal Pradesh, told IANS.
Meanwhile, police officials quoting eyewitnesses said the helicopter may have crashed at Hostalam between Borum and Toru area.
The Advanced Light Helicopter (ALH) of the IAF engaged in flood rescue mission in the state went missing on Tuesday at 3.50 pm after it took off from Pilputu Helipad near Sagalee for the Naharlagun heliport.
The helicopter was evacuating people stranded in Sagalee and Dambuk due to massive landslides caused by heavy rains.
Tezpur-based Defence spokesperson Lt Col Sombit Ghosh said the chopper had gone out for flood rescue operations from its base in Jorhat on Tuesday morning.
Papum Pare district official J.Pertin said the IAF helicopter which was pressed into evacuation of people stranded due to floods in Sagalee, had made five sorties since it arrived there at around 10.30 am on Tuesday.
"In the sixth sortie to Naharlagun, for unknown reason, the crew did not take the last batch of nine civilians and took off from Sagalee with just one policeman, who was deployed to help the two crew members and then went missing," Mr Pertin told IANS.
On Tuesday, Chief Minister Pema Khandu had said in a tweet that 169 persons had been evacuated from Sagalee and Dambuk by the Indian Air Force during the day till then.
"Successfully evacuated 169 stranded people that include women, children from flood affected areas of Sagalee and Dambuk through IAF," Khandu said.
In May, two pilots of the Indian Air Force in Sukhoi-30 fighter jet crashed near the Assam-Arunachal Pradesh border.
In 2015, a Pawan Hans helicopter with three persons on board, including Tirap Deputy Commissioner Kamlesh Joshi, crashed in a dense jungle. Mr Joshi was killed in the crash.
In 2011, the then Arunachal Pradesh Chief Minister Dorjee Khandu and four others died after their Pawan Hans chopper crashed at a remote location in the state.
A few days later, another helicopter crashed while landing in Tawang, killing 16 people.
Following the crashes, commercial chopper services were stopped in the state till 2013 when Pawan Hans restarted the service in Arunachal Pradesh and other parts of the region.
Pawan Hans Helicopter Services Limited (PHHL) has been operating chopper services across Arunachal Pradesh, Sikkim, Meghalaya, Nagaland and Tripura and daily Guwahati-Tawang services for over 15 years.
It is one of the major lifelines in the landlocked and mountainous Arunachal Pradesh.
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