March 11 (UPI) — Medical device maker Stryker is experiencing a global tech issue Wednesday from a cyberattack by a group of pro-Iranian hackers.

Employees found their work devices locked up with the symbol of the hacker group Handala displayed on their screens. It is being described as a “wiper attack,” not meant to extort money but to cause maximum damage to Stryker’s systems.

Handala has claimed responsibility for the cyberattack in a social media post, writing that it is retaliation for the deadly strike on the Shajareh Tayyiba girls school in Minab, Iran.

“We announce to the world that, in retaliation for the brutal attack on the Minab school school and in response to ongoing cyber assaults against the infrastructure of the Axis of Resistance,” the post reads. “In this operation, over 200,000 systems, servers, and mobile devices have been wiped and 50 terabytes of critical data have been extracted.”

The cyberattack has not only impacted employees in the United States but also employees in Ireland.

“Stryker is experiencing a global network disruption to our Microsoft environment as a result of a cyberattack,” Stryker said in a statement. “We have no indication of ransomware or malware and believe the incident is contained. Our teams are working rapidly to understand the impact of the attack on our systems. Stryker has business continuity measures in place to continue to support our customers and partners.”

Stryker is headquartered in Portage, Mich., and employs 50,000 people worldwide, including about 1,000 at its headquarters. It manufactures an array of medical equipment including orthopedic implants, surgical instruments and imaging systems. It is one of the largest medical technology manufacturers in the world.

The headquarters closed for the day on Wednesday with signs posted on its doors warning workers not to access Stryker’s network, use its devices or connect to its WiFi.