Shoes, clothes and a carpet in a mosque in Bath were urinated on during prayers, police have said.
Police released a picture of two men they want to speak to
Avon and Somerset Police are treating the incident at the mosque on Pierrepont Street as a hate crime.
Younus Alzaabi, who was in the mosque when the crime took place, said: "We were praying at the time and heard shouting. It was distracting."
Ch Supt Olivia Pinkney, of Avon and Somerset Police, added: "This was a disgusting and mindless crime."
Police have released CCTV images of two men they want to speak to in connection with the incident.
Bath Liberal Democrat MP Don Foster said he had written to the mosque's leader, Imam Rashad Amazi, expressing his concern.
"I was horrified to hear about what happened at the mosque on Friday and I am confident that the vast majority of local people will share my outrage at this behaviour.
"It is vital that the community works together to say to the minority of mindless criminals who carry out this kind of behaviour, that hate crime will not be tolerated in this city."