ABUJA—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 …