People line up to buy movie tickets outside Regal Cinemas Old Mill 16 in Bend in this file photo from 2015.

Regal Cinemas, which operates movie theaters in the Old Mill District, will temporarily suspend operations at its 536 theaters in the United States and all of its locations in the United Kingdom as of Thursday.

The announcement comes in response to challenges posed by COVID-19 and the theatrical landscape, Cineworld, the parent company of Regal Cinemas, said in a statement Monday.

“This is not a decision we made lightly and we did everything in our power to support a safe and sustainable reopening in the U.S. — from putting in place robust health and safety measures at our theaters to joining our industry in making a collective commitment to the Cinema Safe protocols to reaching out to state and local officials to educate them on these initiatives,” said Mooky Greidinger, Cineworld CEO in a prepared statement.

Regal had reopened theaters with COVID-19 protocols in Albany, Bend, Salem and Eugene in August. Locations in the Portland area remained closed.

In some major markets, like New York, without established reopening protocols, studios have been reluctant to release new films, the company said.

Regal Cinemas has operated a 16-screen complex at the Old Mill District since 2000, said Carrie Ramoz, Old Mill marketing director.

“Regal has brought blockbusters, independent releases, international and local films, live and recorded operas and ballets and more to the theater in the Old Mill District for the past 20 years,” Ramoz said. “They provide an incredible theater experience, and we know many moviegoers who will miss the in-person thrill of the big screen during this closure.”

It is unknown how the closure will affect the 40,000 employees companywide. The theater chain did not file a Worker Adjustment and Retraining Notification in Oregon, which indicates the number of employees who will be out of work.

Other theater chains, including AMC and Cinemark, have reopened with safety precautions in Oregon, but theaters in the Portland area remain closed due to state COVID-19 guidelines. In Central Oregon, some theaters, like the Redmond Odem Theater Pub, have been reopened since May 15.

“We have been open, and we expect to remain open as we move forward,” said Ted Eady, owner of the 40-seat Redmond Odem Theater Pub. “By the middle of June, we saw numbers like we had pre-COVID-19 during slow weeks.”

Greidinger said in a statement that despite no known evidence linking COVID-19 cases to cinemas, the key market of New York still is closed.

“The prolonged closures have had a detrimental impact on the release slate for the rest of the year, and in turn, our ability to supply our customers with the lineup of blockbusters they’ve come to expect from us,” Greidinger said.