Police in Falls Church, VA evacuated an office building that houses an abortion clinic for the second time Thursday, NBC’s Julie Care reports.

#BREAKING: Falls Church building where fireworks exploded in elevator earlier is being evacuated for a 2nd time. Houses abortion clinic pic.twitter.com/tLW9NFsRVb

— Julie Carey (@JulieCareyNBC) April 27, 2017

Explosives sniffing k9 working in the parking lot of the Falls Church building evacuated due to bomb threat @nbcwashington pic.twitter.com/FNlBRKgoYC

— Julie Carey (@JulieCareyNBC) April 27, 2017

The second evacuation comes after Falls Church police and fire units responded to sounds of an explosion around 9 a.m. Fire investigators told the Falls Church Patch they found exploded fireworks in the elevator, and re-opened the building around 9:30 a.m.

Following reports of a second incident Thursday afternoon, Falls Church Police reportedly taped a message to the door saying the building was closed for an investigation into a possible bomb threat.

4/27 Report of a 2nd incident at 900 S.WashingtonSt., a bomb threat. PIO en route, more to come. Earlier fireworks were set off in elevator.

— City of Falls Church (@FallsChurchGov) April 27, 2017

Falls Church Healthcare Center abortion clinic is located in the building, and frequently draws protests from anti-abortion organizations. As Falls Church News-Press reports, “last month, a 50-person prayer was held outside the building for the ’40 Days of Life Campaign.’”