Abuja - Islamist group Boko Haram on Friday beheaded 11 of its own fighter, said an official representing witnesses to the killings.
The 11 were executed because they had left a Boko Haram camp in Sambisa Forest and wanted to surrender to the government, said Mahmud Babagana from the National Union of Road Transport Workers, members of which were witnesses to the murders.
"The truth is that many of these guys are tired of killing and are beginning to repent. But [Boko Haram] won't let them do that," he added.
The killings took place in Miringa village in Borno state.
Meanwhile, two female suicide bombers on Thursday killed 11 people on a roadside in Borno state, according to the website Sahara Reporters.
The Thursday killings followed those of about 150 people in Borno villages earlier in the week.
"I'm finished, my world has crumbled," said Bukar Baba Ibrahim from the village of Kukawa, where about 100 people were slaughtered in mosques and in their homes.
Ibrahim said he had lost his three children, his father, his six siblings and his uncle in the attack.
"Being alive does not have any meaning to me now. I have lost all my people and I am all alone, no relatives, no house, because they burned our house with my people inside it. It would have been better if I had not survived," he said.
European Union foreign policy chief Federica Mogherini condemned the killings and expressed confidence that "the Nigerian authorities will continue to fight terrorism with the utmost determination and urgency, respecting rules for engagement."
Earlier this week, a government official said 47 former Boko Haram members had joined a new programme allowing former terrorists to become reintegrated into society.
Since 2009, Boko Haram has killed more than 10 000 people in northern Nigeria in its campaign to establish an Islamist state.