It happened in the village of Alkali in the north-eastern state of Yobe.
The police spokesperson in the state, Dungus Abdulkarim, told the BBC that the two young men had engaged in a fight in which they used machetes to cut off each other’s left hand.
They’re both aged 25.
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It’s not yet clear what exactly caused the family fight but the police say it’s apparently related to a farming issue.
The authorities have now taken the amputated hands to a hospital.
The two cousins are in a critical condition and are being treated at a medical facility.
Source: BBC