An overnight curfew was imposed in Nigeria's southern Rivers state as tensions ran high over local results of the country's general election, the state government said on Monday.
"The government has imposed a curfew in Rivers state from 7:00 pm (1800 GMT) to 6:00 am to prevent the breakdown of law and order because of the tense political situation," said information commissioner Ibim Semenitari.
Rivers, in the oil-producing Delta region, is seen as a key battleground. The main national opposition has held protests in the state capital Port Harcourt, accusing the ruling party of widespread vote-rigging.