Nigeria's leader declared an emergency in oil-rich Rivers state and suspended its governor and lawmakers Tuesday over a political crisis and vandalism to pipelines that contribute to the country's status as Africa's top oil producer.

A crisis in Rivers has brewed for months between incumbent Gov. Siminalayi Fubara and state lawmakers, many of whom are backed by his predecessor. This week, some lawmakers initiated an impeachment process against the governor, accusing him of various illegalities regarding the presentation of the state budget and the composition of the legislative chamber.