Madrid’s Teatro Real was among the world’s first opera houses to reopen amid the coronavirus pandemic, presenting a socially distant staging of La Traviata earlier this summer. But as Spain faces a resurgence of infections, audiences have proven that it’s not yet time to relax restrictions.

The September 20 performance of Verdi’s Un Ballo in Maschera ended abruptly moments into its first act, following continued protests from audience members.

Due to concerns over a lack of socially distanced configurations in upper levels of the venue, patrons began clapping and shouting, causing a delay and, after two attempts from conductor Nicola Luisotti, an eventual halt to the entire performance.

The theatre says that 905 seats (about 51.5 percent of the capacity) were occupied, putting it below the city’s guidelines of limiting audiences to 75 percent. In response to the protests, ticketholders were offered the possibility of returning tickets or relocating, with about 200 patrons taking up the latter offer. Teatro Real says it will implement this practice before the start of performances moving forward.

“The management of the Teatro Real will open an investigation to find out this unfortunate incident, and will take the necessary measures so that the successive functions develop normally,” the company said in a statement.