New York CNN Business  — 

Six employees at a Buffalo Starbucks that recently voted to join a union walked out just before 9 am Wednesday citing health concerns, prompting the temporary closing of the store.

Starbucks said it had closed that location and others in the city to in-store customer traffic Monday, restricting them to take-out only service due to a rising number of Covid cases in the area.

Limiting stores to take out service also allows the locations to operate with fewer employees — referred to as “partners” at Starbucks — which is helpful given that many workers are unavailable due to the surge in Covid cases. Starbucks decided to close the Buffalo store rather than keep it open with staff from other locations once the workers walked out Wednesday, Starbucks spokesperson Reggie Borges said.

“For the last two years we exceeded all safety standards to make sure our partners are safe,” Borges said. He added that unlike many other food service companies and retailers, Starbucks provides sick pay as well as full pay for up to two self-isolation periods. This week the company also announced it will require all of its employees to either show proof of vaccination or be tested weekly for Covid-19.

Starbucks Workers United, which won the December vote at the Buffalo store where workers walked out, said the coffee chain has not been doing enough to protect employees from the pandemic. The union wants workers to be able to enforce mask mandates for customers, and for Starbucks to provide employees with N95 masks, Covid testing kits and hazard pay.

Workers in the Buffalo store “have been pressured to work by Starbucks despite understaffing and health concerns,” the union said in a tweet Wednesday. “We believe everyone deserves the right to feel safe at work! Partners will return when it’s safe to do so.”

Borges said that three of the Starbucks workers at the Buffalo store remained on the job when their co-workers walked out Wednesday.

The store has been operating with reduced staff due to employees calling in sick from Covid cases or exposure, said Casey Moore, a union supporter who works at a different, nonunion Starbucks. She said she didn’t know when the workers might be willing to return to work.

“The partners intend to return when they believe it is safe to return,” she said, adding that workers remained on the picket line outside the location even after it closed for the day.

In December, the workers became the first employees atanycompany-owned Starbucks to vote to be represented by a union. They have yet to negotiate a contract with the company.

Workers at a second Starbucks in Buffalo voted not to unionize, while the results of a union vote at a third location in the city has yet to be determined due to challenged ballots. Workers at several other Starbucks in New York and other states have also filed asking for union representation.