The aerial search was called off for the day because of bad weather.
"According to inputs from the Arunachal government, local people have have sighted something like an aircraft inside Bhutan. It`s about five km inside Bhutan from the border. Having got the clearance from Bhutanese authorities, one of our teams started on foot this morning," ITBP IG M S Bhurji told PTI.
The team, comprising about 35 men, is expected to reach the spot before night.
Another ITBP team from Dirang in East Kameng district in Arunachal Pradesh started for Nagajiji near Sela Pass after infra-red images from IAF Su30s detected an `aircraft-like` object, he said.
"We have searched the Nagajiji area earlier, but this time the search would be intense," he said.
It might take close to 10 hours for the men to reach because of hazardous terrain and steep gradients about 14,000 ft above sea level with bad weather making the trek difficult.
Around 250 ITBP personnel have fanned out mostly around the Sela Pass and another 60 men were likely to be deployed soon, the IG said.
The force had launched and unsuccessful search in the Lungthung area yesterday.
Satellite images from RISAT-2 reportedly traced a few metal parts in the area, which may be parts of a helicopter, government spokesperson Jarbom Gamlin said in Itanagar.
The ground search was being made by 3,000 personnel from the Indian Army, ITBP and SSB with the assistance of the state police, defence sources said.
Two IAF Mi-17 choppers took off from Tawang in the morning and after a 45 minute sorties had to return from Sela Pass because of thick haze over the mountains.
Four MI-17 choppers were stationed at Tezpur for search operations if the weather improved, defence spokesman N N Joshi said.
"The search was based on the imagery from ISRO and aerial mapping by Sukhoi fighters from Bareilly," Lok Sabha member Takam Sanjay, who is heading a high-level team at Dirang to monitor the rescue and search operations, told PTI when asked about the detection of an `aircraft-like` object on the ground.
A Pawan Hans chopper was stationed at Dirang, he said.
There were 50 commands at the disposal of the team, whose other members were State R D Minister Takar Marde and DIGP (Intelligence) Anil Sukhla.
Meanwhile, the crisis management committee has been meeting twice to monitor the situation and was being attended by central ministers V Narayansamy and Mukul Wasnik, AICC general secretary Dhaniram Shandil and secretary Sanjay Bapan.