German authorities reportedly moved to ban the use of the mobile version of video conferencing service Zoom, due to fears over the security of the system.

Reuters reported the German Federal Foreign Office ordered officials not to use the Zoom Cloud Meetings app, restricting use of the conferencing tool to fixed-connection computers.

Local newspaper Handelsblatt added the ministry called for the block after concluding Zoom’s software had critical weaknesses, and security and data protection problems. However, an outright ban was not possible because the service is widely used by international partners of the foreign ministry.

Zoom faced growing scrutiny of its security set-up in recent days, with US state attorney generals initiating a probe after a number of reports of unidentified individuals invading meetings.

The company previously pledged to up its game, reportedly hiring former Facebook security head Alex Stamos as an adviser, and creating an advisory board to examine its privacy practices.