Cardiff University’s main building has been evacuated after a chemical spill.
Emergency services were called to the “contained incident” on the city’s Park Place at 11:13 BST on Tuesday.
The university said there were no reported injuries but a “small number” of people were being checked by paramedics as a precaution.
South Wales Police said the road between Museum Place and Cathays Terrace was closed and urged people to avoid the area.
The Welsh Ambulance Service said it sent a rapid response vehicle and two emergency ambulances to the scene after being alerted to the incident.
A spokesperson said paramedics were being supported by the Hazardous Area Rescue Team.
Cardiff University said the main building will remain temporarily closed “until we are confident there is no risk to health and safety”.