Security guards providing protection at California offices for Anthropic, Google, OpenAI, and other tech companies plan to strike this week, which could prompt some firms to close offices or require employees to work from home. According to ChainCatcher, the guards submitted a 72-hour strike notice on Tuesday morning local time and plan to refuse shifts starting at 4:30 a.m. on Friday.

The Western regional branch of the Service Employees International Union said the guards who may join the strike are responsible for sites used by Amazon, Microsoft, Salesforce, OpenAI, Anthropic, Google, Meta, and Nvidia. Bay Area tech companies have not yet announced office closures because of the dispute.

The labor dispute involves security firms Allied Universal, Securitas, and GardaWorld, with the union representing about 14,000 security guards in California. Negotiations over a new labor contract have continued for months, with workers seeking higher pay, better health coverage, and improved job training.

A union spokesperson said talks will continue on Wednesday and Thursday, and the strike was still not final as of Tuesday. The union also planned a march in downtown San Francisco on Tuesday ending at Salesforce Tower, where Salesforce is headquartered. On September 3, security guards voted at a rally in San Francisco to authorize a strike.