“All 31 have not been seen since yesterday and it is obvious they were seized by Boko Haram,” said Umar Kachalla, a militia in Gamboru fighting Boko Haram alongside the military.
Two weeks ago, Boko Haram gunmen shot dead 10 loggers from Gamboru in the bush outside Wulgo while collecting firewood, said another militia Shehu Mada.
“We believe Boko Haram abducted them to use them as fighters, given their young age,” Mada said.
“They (Boko Haram) abandon the bodies of their victims when they kill them but the fact that the bodies of the loggers have not been seen is clear indication they were abducted,” said Mada.
Boko Haram fighters still operate in hard-to-reach rural areas where military operations are minimal.
In August 2014, the group seized Gamboru, a trading hub along with the neighbouring town of Ngala.
Nigerian troops retook both towns in September 2015 with the help of Chadian forces following offensives lasting months.
Despite the recapture of the area, Boko Haram fighters continue to launch sporadic attacks, ambushing troops and vehicles, as well as attacking and abducting farmers.
Last week two farmers were shot dead by jihadists while harvesting their crops in Bugda village outside Gamboru, according to resident Nasiru Saidu.
Boko Haram’s eight-year insurgency against the government of Nigeria has spilled into neighbouring Niger, Chad and Cameroon, killing around 20,000 people and displacing more than 2.6 million.
Most of the displaced rely on food handouts from aid agencies while others have turned to felling trees in the arid region for firewood which they sell to buy food.
The jihadists have increasingly targeted loggers in their armed campaign, accusing them of spying and passing information to the military and the local militia fighting them.
On Christmas Day the jihadists killed 25 loggers at a logging site outside the city of Maiduguri.