The Chicago Tribune newsroom was hit by a round of layoffs Thursday.

It wasn’t clear how many people lost their jobs. Marisa Kollias, spokeswoman for the newspaper’s parent company Tronc, said the newspaper “is reshaping its newsroom and making important steps in an ongoing effort to become more a digital enterprise.”

“Excellence in journalism remains our top priority. The newsroom is redefining jobs and structure so that people are in the best position to create and deliver news content for the rapidly changing demands of our audience,” Kollias said.

Employees did not receive notice of the impending job cuts.

“Everyone who walks out of the newsroom with their things gets a round of applause,” Tribune crime reporter Peter Nickeas tweeted Thursday afternoon. “Nobody has communicated to the newsroom about what’s going on.”

More than a dozen newsroom positions were eliminated in the Tribune’s last round of layoffs in October, sources said. The latest job cuts were announced shortly before the newspaper’s move from their iconic Tribune Tower to Prudential Plaza, and a month after Tronc sold the Los Angeles Times for $500 million.

Media critic Robert Feder reported that a group of Tribune staffers met last week with the Chicago News Guild — the union that represents Chicago Sun-Times journalists — for a meeting “described as preliminary to a full-scale organizing effort.”

Tribune publisher and editor-in-chief Bruce Dold sent a memo to employees about the “challenging time.”

“In the coming days we will work with you to determine your assignments and responsibilities so you know exactly what your role will be,” Dold wrote.

“Today, we took the most difficult step in this transformation. We notified a number of employees that their positions are being eliminated. I know the impact this has on everyone in our organization. That impact is by far most profound on those who are directly affected. I want to thank them for the work they’ve done for the Tribune.”