Nigeria said on Friday it had indefinitely suspended Twitter's activities, two days after the social media giant removed a post from President Muhammadu Buhari that threatened to punish regional secessionists.

Information Minister Lai Mohammed said the government had acted because of "the persistent use of the platform for activities that are capable of undermining Nigeria's corporate existence".

Mohammed did not spell out what form the suspension would take or give more details on the undermining activities. His ministry also announced Twitter's suspension on Twitter.

When asked about the details of the suspension, a ministerial aide told Reuters: "Wait and see how things will turn out."

As of the early hours of Saturday, Twitter's website was inaccessible in Nigeria on some mobile carriers, while its app and website worked on others, according to Reuters tests in Lagos and Abuja.

Twitter is investigating its "deeply concerning" suspension of operations by the Nigerian government, and "will provide updates when we know more," the company said in a statement.

On Wednesday, the US tech firm said Buhari's post threatening to punish groups blamed for attacks on government buildings had violated Twitter's "abusive behaviour" policy.

In April, the information minister reacted angrily when Twitter chose neighbouring Ghana for its first African office. He said the company had been influenced by media misrepresentations of Nigeria, including reports of crackdowns on protests last year.

Demonstrators calling for police reform had used social media to organise, raise money and share alleged proof of police harassment. Twitter's chief executive, Jack Dorsey, tweeted to encourage his followers to donate.

In the protests' wake, Mohammed called for "some form of regulation" on social media to combat "fake news".

A spokesperson for Airtel, one of Nigeria's largest mobile carriers, on Friday declined to say whether the company had received any government directives about the suspension.

MTN, the largest mobile carrier, did not respond to calls and a message seeking comment.