Google said on Thursday it had terminated 28 employees after some staff participated in protests against the company’s cloud contract with the Israeli government.

The Alphabet said a small number of protesting employees entered and disrupted work at a few unspecified office locations.

“Physically impeding other employees’ work and preventing them from accessing our facilities is a clear violation of our policies, and completely unacceptable behavior,” the company said in a statement.

Google said it had concluded individual investigations, resulting in the termination of 28 employees, and would continue to investigate and take action as needed.

In a statement on Medium, Google workers affiliated with the No Tech for Apartheid campaign called it a “flagrant act of retaliation” and said that some employees who did not directly participate in Tuesday’s protests were also among those Google fired.

“Google workers have the right to peacefully protest about terms and conditions of our labor,” the statement added.

The protesting faction says that Project Nimbus, a $1.2 billion contract awarded to Google and Amazon.com in 2021 to supply the Israeli government with cloud services, supports the development of military tools by the Israeli government.

In its statement, Google maintained that the Nimbus contract “is not directed at highly sensitive, classified, or military workloads relevant to weapons or intelligence services.”

Protests at Google are not new. In 2018, workers successfully pushed the company to shelve a contract with the US military, Project Maven, meant to analyze aerial drone imagery with potential application in warfare.