FILE PHOTO: Nigerian President Muhammadu Buhari at the United Nations General Assembly in New York, September 28, 2018. REUTERS/Darren Ornitz/File Photo

LAGOS (Reuters) - A special police force has been deployed to flashpoints in the northern state of Kaduna on Sunday in the wake of communal violence over the last few days that has killed 55 people, President Muhammadu Buhari said on Twitter.

“The police have been authorized to do everything possible to restore calm,” he said in the tweet.

The Kaduna state government imposed a 24-hour curfew on Sunday after violence broke out on the streets of the state’s capital city, also called Kaduna.