A man was taken to hospital after an assault at a mosque last week.
Officers said a man in his 40s received serious injuries following a dispute at the Jamie Mosque and Bangladesh Islamic Centre in Hatfield Road.
The incident happened at around 11.35pm last Thursday (June 4). The man who is still in hospital suffered injuries including a fractured rib.
Police said it is believed a small group of men were involved.
Officers believe it is not a hate crime and said all parties have an affiliation to the mosque.
Officers are appealing for anyone with any information to come forward to help with their enquiries.
Neighbourhood Inspector Andy Wiseman said: "We are appealing for anyone who saw what happened to contact us, as we know there were people at the Islamic Centre on Thursday evening.
"Anyone with any information about the incident is asked to make contact so we can piece together exactly what happened prior to the man receiving these injuries.
"We do not believe this to be a hate crime. All parties have an affiliation to the mosque.
"We are thoroughly investigating this incident and will be looking to take positive action against those responsible for this serious assault."
Anyone with information is asked to contact Detective Sergeant Paul Wadsworth from the local crime unit directly via email at paul.wadsworth@herts.pnn.police.uk.
You can reporter information online at herts.police.uk/report, or you can call Crimestoppers anonymously on 0800 555 111.
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