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What was described as a “bizarre” and “violent” encounter with the paper’s publisher has prompted dramatic action from the union at the Pittsburgh Post-Gazette.

The alleged incident occurred last Saturday night when, according to a detailed account by the Newspaper Guild of Pittsburgh, John Robinson Block arrived in the paper’s newsroom with his daughter.

Block, the publisher of the Post-Gazette, was described as intoxicated and belligerent by four separate eyewitnesses, whose accounts were published online Wednesday by the Guild.

The Guild has requested that Block address his “personal issues” before he is “allowed to return to the newsroom and be around his employees, both for our safety and his.” (Block was back in the office on Thursday but has not yet addressed the matter, according to Michael Fuoco, an enterprise reporter at the Post-Gazette and the president of the Guild.)

Additionally, the Guild has filed an unfair labor complaint with the National Labor Relations Board over Block’s conduct.

The complaint, a copy of which was shared with CNN Business, said that Block “[threatened] employees with shop closure or job loss unless they cease engaging in union or other protected concerted activity.”

A spokesperson for the NLRB confirmed that the complaint was filed.

John Robinson Block and his brother Allan Block, who serves as chairman of Block Communications Inc., did not respond to a request for comment; a message left at Block Communications Inc. was unreturned.

Marianne Mizera, a web editor at the paper, said that Block arrived in the newsroom with his daughter around 10 p.m., and he was “immediately yelling about various topics, pointing and waving his finger repeatedly up in the air and swinging his arms.”

“He was very angry and irate,” Mizera said, who added that it was “clear he was intoxicated.”

The eyewitnesses said that Block was made angrier by a sign posted to a Guild bulletin board in the newsroom protesting the company over a dispute related to health care costs.

“He was going crazy over the ‘Shame on the Blocks’ sign on the guild bulletin board and demanded that someone take a photo of him and his daughter in front of it,” said Andrew Goldstein, a night cops reporter at the paper. “She was screaming that she didn’t want to, crying hysterically and red-faced. I felt terrible about what I was watching.”

Goldstein said that Block ranted about the Guild’s leadership and said he was going to fire various editors and managers, all while “slapping and kicking the wall near the ‘Shame on the Blocks’ sign, and pounding his fists.”

Carl Remensky, who works on the sports desk, also witnessed the moment near the sign.

“Eventually he got his daughter in front of the same Guild bulletin board,” Remensky said. “At one point she appeared very distressed and I saw he had hold of her, with his arms around her waist, trying to pull her back in front of that bulletin board. She appeared to be crying and yelling and appeared doubled over as she tried pull away from him. She got away and Block remained standing at the bulletin board, shouting and slapping the ‘Shame’ poster.”

Goldstein said he was “horrified” by what he saw.

Alex Miller, a paginator, backed that assessment.

“I’ve been working in newsrooms for more than a decade, and this is most bizarre thing I’ve seen,” Miller said. “[Block] behaved in a way that would get any ordinary employee fired on the spot and escorted out of the building for everybody’s safety. He appeared totally out of control. He was loud and violent, and it was frightening to witness because he was so erratic. There was no way for anybody to know what he might do next.”

The Guild said it was prompted to make these accounts public after seeing a “false narrative” pushed by Allan Block. Block Communications Inc. is the owner of the Post-Gazette, as well as the Toledo Blade and several television stations.

“The frustration over financial and other challenges in the newspaper industry led to an unfortunate exchange with employees of which I have been made aware,” Allan Block said in a statement earlier this week. “Block Communications regrets if anyone present may have misconstrued what occurred as anything other than an indication of strong concern and support for the legacy and future of the Post-Gazette. We want the entire staff to know that we will continue to value all of our employees and their contributions to the PG.”

In its release on Wednesday, the Guild fired back at those claims, taking exception to Allan Block’s attempts to “whitewash” what transpired.

“To blame John Block’s erratic, menacing and disturbing conduct on ‘financial and other challenges in the newspaper industry’ is cowardly, despicable and a blatant lie,” the Guild said. “The Guild believes that John Block has personal issues that must be addressed before he is allowed to return to the newsroom and be around his employees, both for our safety and his. We are distraught over his interaction with his daughter and are highly concerned for her well-being.”