Nonemergency surgeries, procedures and medical visits were canceled or suspended at multiple hospitals across the country Friday amid a global software outage that has kept health care workers from accessing medical records, prescriptions, scheduling, and other electronic tools and documents.

Massachusetts General Hospital in Boston, the states largest, said it has canceled all previously scheduled non-urgent surgeries, procedures, and medical visits due to the outage linked to the cybersecurity firm CrowdStrike.

The outage is said to have primarily affected computers using the CrowdStrike software with Microsofts Windows operating system.

The hospital said in a statement that its clinics and emergency departments remain open to patients with urgent health concerns, and we continue to care for all patients currently receiving care in our hospitals.