MTN Nigeria said on Wednesday it notified some enterprise customers about a potential service disruption to enable them put in place business continuity measures.
The local unit of South Africa's telcoms firm MTN runs Nigeria's largest mobile phone network which generates around a third of the company's revenue.
The action was "a routine notification to a small group of businesses affected by a specific challenge in very few specific locations," MTN said.
"Maintaining network stability and high levels of customer service remains a key priority for us," Karl Toriola, MTN Nigeria's chief executive, said in a statement.
Toriola said MTN aimed to inform customers in a timely manner so that they can put in place business continuity measures. Potential disruptions could be due to network maintenance, faults or other circumstances that may pose a risk, he said.
On Tuesday, MTN had sent a customer notice, seen by Reuters, informing them that services could be disrupted due to rising insecurity in different parts of the country.