The governor of Lagos state declared a 24-hour curfew across Nigeria's biggest city on Tuesday, as he said protests sparked by police violence had "degenerated into a monster". "We will not watch and allow anarchy in our dear state," Babajide Sanwo-Olu said on Twitter, as he declared the measure with effect from 4 pm (1500 GMT), adding that "nobody except essential service providers and first responders must be found on the streets". ldh/del/gd