ATHENS (AP) — Two Bulgarian women have gone on trial in Athens for allegedly vandalizing centuries-old artefacts in three museums by smearing them with an oily liquid.

Police say the women, who were arrested Sunday in the National Historical Museum of Athens, claimed they didn’t want to cause damage. Instead, they allegedly said their motives were religious as they wished to “purify” the artefacts — all Christian-era — with oil and scented water.

In a statement Monday, police said museum guards, on the alert after two similar attacks in recent weeks, saw them smearing a frame containing religious artefacts and called the police. Officers confiscated three bottles of oil in the suspects’ possession.

Many of the damaged artefacts required extensive conservation.

The trial was adjourned Monday to allow chemical tests on the liquid.