NEW YORK (AP) — Zoom is experiencing partial outages during the first day of school for thousands of students who are relying on the video conferencing technology to connect with educators.

The company said Monday that it began receiving reports of disruptions around 7 a.m. Mountain time. It has identified the issue causing the problem and is working on a fix, it reported on its status page.

Grade schools, high schools and universities are relying on Zoom and competing technologies like Microsoft Teams to reduce the chance of infection during the pandemic.

Technical issues are occurring across the U.S., with the most reports on the East Coast, as well as in Europe, according to downdetector.com, which monitors self-reported outages.

Zoom Video Communications became a familiar tool to millions of new users after the spread of COVID-19 made face-to-face meetings risky. It now has about 300 million users.

It suffered some growing pains during the early months of the pandemic, such as “ zoombombers ” who crashed meetings, but successfully went public in April.

The cause of the outage was not immediately known, but of those reporting issues, 70% reported problems logging in, according to reports.