Anthropic announced that its artificial intelligence models had breached three different organizations during cybersecurity tests that went awry, a little more than a week after its chief rival, OpenAI, disclosed a similar incident.

Anthropic said in a blog post Thursday that it made the discovery after performing a review of its own cybersecurity tests, following OpenAI’s announcement of a breach. In both the OpenAI and Anthropic tests, the AI models were able to access the internet from within testing environments that should have been sealed off, according to Anthropic’s blog.

The company said it reviewed 141,006 evaluation tests and found three instances in which its Claude AI tool accessed the internet and then hacked into “the real-world infrastructure of external organizations.” The earliest incidents date to April, the company said.