A police officer is in hospital with serious injuries after being slashed with a sword.
The attack happened at about 13:50 BST in Demesne Road, Whalley Range, Manchester .
Officers were responding to reports of an armed man threatening people, Greater Manchester Police (GMP) said.
A man, 23, has been arrested on suspicion of possession of a bladed article and assaulting a police officer.
GMP said, on arriving at the scene, police tried to engage with a man before one of the officers was slashed with a sword.
The officer’s injuries are not thought to be life-threatening.
A number of streets around Demesne Road are cordoned off while investigations continue.