What you need to know:
- The victims had been logging at the site for seven months without incident as they were always escorted by troops to protect them from jihadists.
- On Saturday they went to the logging site without security escort and informants could have alerted Boko Haram that the loggers had no security protection. They were attacked.
- Boko Haram's eight-year campaign of Islamist violence has killed more than 20,000 people and displaced some 2.6 million from their homes.
The number of loggers killed in a Boko Haram attack in northeast Nigeria has risen to 25 following the discovery of more victims, survivors and militias said on Sunday.
Motorcycle-riding gunmen attacked a logging site where people were loading firewood into vehicles some 20 kilometres from the state capital Maiduguri on Saturday.
Four bodies were initially recovered, but search teams later found 21 more victims in the surrounding area.
"We found 21 more bodies after search teams combed the bushes when many people didn't make it back to the village after we were attacked," logger Bunu Gana, who survived the attack, told AFP.
Another logger, Haruna Dahiru, said: "Fifty-three of us set out to the logging site from Bakin Muna (village) but only 28 made it back after the attack.
"We found four bodies at the site which made us to search for those missing."
Boko Haram's eight-year campaign of Islamist violence has killed more than 20,000 people and displaced some 2.6 million from their homes, sparking a dire humanitarian crisis in the region.
Most of the displaced rely on food handouts from aid agencies while others have turned to felling trees in this arid region for firewood which they sell to buy food.
The loggers were displaced by Boko Haram from nearby Mujtari, Zangale, Anzamala and Kumbulla villages who turned to logging to feed their families, militia leader Ibrahim Liman said.
He said the victims had been logging at the site for seven months without incident as they were always escorted by troops to protect them from jihadists.
"Yesterday they went to the logging [site] without security escort and it was evident some informants alerted Boko Haram that the loggers had no security protection," he said.
The attackers were believed to have come from Boko Haram's main enclave in Sambisa forest which is accessible from the logging site, he said.
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.
In August Boko Haram fighters decapitated three loggers near Aisa-Wulomari Village, 40 kilometres from Maiduguri, while returning to the city.
In April eight loggers were killed and their bodies burnt by the insurgents at Kayamla Village, 10 kilometres from Maiduguri, while collecting firewood in a bush.