A second night of unrest — triggered by a Sudanese man’s alleged knife attack on a man in the middle of a Belfast street — leaves 12 officers injured and 16 rioters in custody.

U.K. officials hope to avoid a repeat of last summer’s anti-immigrant violence.

Belfast police appealed for calm after a violent knife attack caught on videophone prompted calls for anti-immigration protests. This followed a week of migration-related riots…