AT LEAST 13 protesters have been killed in Nigeria as mass demonstrations against the country’s economic crisis turned violent in several states, Amnesty International said today.

Four of the protesters were killed by a bomb explosion in the north-eastern state of Borno that also left 34 injured, police said on Thursday night.

More than 300 demonstrators were arrested and curfews imposed in the northern states of Kano and Katsina after government and public properties were looted, the police added.