A 25-year-old man is in custody after another man sustained cuts to his head and throat in Lurgan, Co Armagh.
The 33-year-old victim was attacked outside a pub in the William Street area of the town in the early hours of Sunday morning.
Chief Inspector David Nixon said the man was treated at hospital for his injuries, which are not thought to be life-threatening.
“We know there was a large crowd socialising in the area last night and we are appealing to anyone who in the vicinity of William Street between 12.15am and 12.30am who witnessed the assault to contact police in Lurgan,” he said.
DUP Upper Bann MLA Carla Lockhart described the attack as brutal.
“My thoughts are with the victim of this brutal attack in the early hours of the morning. It is a very alarming attack and one that I would utterly condemn.
“William Street is renowned for its night time economy and this incident has shocked the local people,” she said. “It is vital that information pertaining to the attack is reported so that they can face the full rigours of the law.”