Nigerian President Muhammadu Buhari says that African mobile phone operator MTN fueled the country’s Boko Haram insurgency by failing to disconnect unregistered sim cards.

Buhari made the comments Tuesday during a visit to Nigeria by South African President Jacob Zuma, the BBC reports.

MTN missed a mid-2015 deadline to disconnect cards, according to the report.

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"You know how the unregistered [sim cards] are being used by terrorists and between 2009 and today, at least 10,000 Nigerians were killed by Boko Haram," said Buhari, during a joint press conference with Zuma. "Unfortunately, MTN was very very slow and contributed to the casualties," he added, in his first public comments on the case.

The phone giant was fined $5.2 billion in October by Nigeria’s telecoms industry regulator for failing to disconnect the cards, although this was later reduced to $3.4 billion. Last month MTN announced that it has paid $250 million in a goodwill gesture towards a possible settlement in the case.

MTN provides service to over 200 million people in Africa and the Middle East. Nigeria is reportedly the phone giant’s largest market.

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The company has not yet responded to a request for comment on this story from

Dozens of emaciated-looking Boko Haram members begging for food have surrendered in northeast Nigeria, the military and a civilian self-defense fighter said last week.

Food shortages could indicate that Nigeria's military is succeeding in choking supply routes of the Islamic extremists who have taken their fight across Nigeria's borders. Some 20,000 people have died in the six-year uprising.

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In the 10 months since he took office promising to halt the insurgency, Buhari has replaced the leadership of the military, moved the headquarters for the fight from the distant capital of Abuja to the heart of the northeastern insurgency and resupplied soldiers.

The Associated Press contributed to this report.