Oscar Gutierrez/CNET

The US National Labor Relations Board is investigating two complaints filed by Apple employees alleging unfair labor practices against the company, according to filings on the agency’s website.

One complaint, filed on Aug. 26, relates to accusations of retaliation, discipline and discharge, while another filed on Sept. 1 alleges threats and promises of benefits. The board’s website says it investigates all charges filed with the agency, and if it determines the complaint has merit, it tries to broker a settlement or pursues legal action against the accused.

Cher Scarlett, a principal software engineer at Apple, confirmed in a tweet Thursday evening she had filed the Sept. 1 complaint.

“These all revolve around unlawful conduct and unlawful rules that have been engaged in over the past 5 months, particularly over the last month,” she said in the tweet, adding in a subsequent tweet that Apple employees should contact the NLRB if they were told “not to participate in the wage transparency survey, not to talk about your pay, or were coercively questioned about it.”

The complaints come as the tech giant faces a wave of employee activism in recent months. In August, employees criticized Apple’s move to scan US customers’ iPhones and computers for images of child sex abuse, worrying it could lead to censorship or arrest by repressive governments. In July, employees began circulating an internal petition pressing executives for more flexible working conditions as the company began laying out post-lockdown return-to-work polices.

Apple didn’t immediately respond to a request for comment but declined to discuss the complaints with Reuters, which earlier reported on the filings.

“We take all concerns seriously and we thoroughly investigate whenever a concern is raised and, out of respect for the privacy of any individuals involved, we do not discuss specific employee matters,” Apple told the news agency.