Shocking pictures shared on social media show the extent of the destruction to the altar area of St Simon’s Catholic Church, Glasgow, including broken statues and other holy relics.
The Archdiocese of Glasgow described the incident as a “shameful attack on a much-loved church.
Officers believe the church was targeted between 1.30pm and 4pm on Monday afternoon when the church was open.
They said the incident was not thought to be sectarian-related or a hate crime offence.
The Archdiocese of Glasgow said: “Let’s find those responsible and send out the message loud and clear that this kind of action is unacceptable.”
A police spokeswoman said: “Between 1.30pm and 4pm on Monday, April 29, vandalism was carried out at St Simon’s church at Partick Bridge Street.
“The church would have been open at the time.”