A man needed hospital treatment when he was assaulted outside a church in Leeds city centre.
Police were called to Mill Hill Chapel in Lower Basinghall Street at around 6.30pm.
They found a 52-year-old man with a cut to the back of his head and a broken nose.
A spokesman said the man had been taken to hospital, but his injuries were not believed to be life-threatening.
He said: "The victim is believed to have been punched to the ground during an argument with another man who left the scene. Enquiries are ongoing."
Officers put a cordon in place and remained at the scene for several hours gathering evidence.
Anyone with information is asked to contact Leeds District CID via 101, quoting crime number 13170389306.