Jihadists have killed 30 men in a revenge attack after their commanders died in military airstrikes in Nigeria's northeast Borno state, two militia leaders said on Tuesday.
The attack was carried out on Saturday in the village of Mudu, in Borno State near the border with Chad by jihadists of the Islamic State in West Africa (Iswap), a government official said.
It was only known on Tuesday because of the poor quality of the communications network, as the jihadists had destroyed several telecommunications relays in the region.
The 30 victims were "scrap metal dealers who were in the area looking for burnt-out vehicles, which are plentiful in the villages of northern Borno because of the terrorist attacks," Babakura Kolo, a militia leader in the regional capital Maiduguri, told AFP.
The men killed in the attack had come on foot from camps for displaced people in the town of Rann, 80km away.
Another militia leader, Umar Ari, said Iswap accused the scrap metal dealers of tipping off the army about their positions in the area.
"The 30 men had the misfortune to be in the area when the terrorists were mourning the death of their two commanders killed in a military operation," Ari told AFP.
In recent weeks, the Nigerian army has carried out successful ground and air raids against ISWAP and rival Boko Haram fighters, killing several jihadi commanders.
ISWAP split from Boko Haram in 2016, and has steadily risen to become the most powerful jihadist group in the region.
Both groups are increasingly targeting civilians, including loggers, farmers and herders, whom they accuse of spying on them.
Jihadist violence has killed more than 40,000 people and forced some 2.2 million to flee their homes in northeast Nigeria since 2009, according to the UN.
Most of the displaced people live in camps and depend on food aid provided by humanitarian organisations. Many are forced to cut down trees in this arid region for firewood and collect scrap metal to sell for food.
Jihadist violence in Nigeria has spread to neighbouring Niger, Chad and Cameroon. To combat it, the armies of the four countries, as well as that of Benin, reactivated in 2015 a Mixed Multinational Force (MMF), created in 1994 but hardly operational since.
The Nigerian government has announced that it will take action to protect the country's people from the effects of the war on the environment, a government official said on Tuesday.