Helsinki police have detained a woman suspected of dispersing an unknown substance at the Torni Hotel Ateljee bar last week, the law enforcement agency announced on Wednesday.

On Friday evening, three bar workers suffered unspecified symptoms after a woman dispersed the substance. Police arrived on the scene and then evacuated the establishment.

Police said on Wednesday afternoon that the female suspect had not yet been interviewed.

An investigation into the incident is ongoing, and authorities were still awaiting lab test results of the unknown material, according to police.

Authorities are investigating the incident as aggravated assault, endangerment to health and safety as well as property damage crimes.