Among others, there are two main growing dangers for places of worship:
Radical Islamism
Right-wing extremism
Places of worship are powerful symbols to send political messages, spread radical ideologies or instill fear. Therefore, they are an easy target for extremists.
How to protect places of worship?
Newsroom: ‘Protection of Places of Worship’
You can find the whole article here: https://ec.europa.eu/newsroom/pps/items/696367/en