The Delaware Art Museum in Wilmington is trying to track down a group of visitors who recently vandalized a number of the institution’s works with stickers. The stickers, which feature some religious script and imagery, were placed on a number of Pre-Raphaelite paintings and an outdoor statue. Other stickers with a large red “T” were also placed on the paintings.

The vandals were captured on the museum’s security cameras, but attempted to hide their identities. The stickers have been successfully removed by a painting conservator, but the amount of damage done to the collection is unknown. The Delaware Art Museum has one of the most celebrated collections of Pre-Raphaelite art outside of Britain.

In March, the Delaware Art Museum announced that it would deaccession four works from its collection to pay off its $19.8 million bond debt and replenish its endowment. The institution has not specified which works it plans to sell.