Slack, the messaging service used by offices around the world, is down due to an unknown issue.

On X, the company said: "We’re very sorry for the inconvenience. We’re working hard to resolve this issue as quickly as possible."

They added: "Our engineers are investigating what's happened. We apologize for the disruption and we hope to be back to normal soon. Please check https://slack-status.com for any updates. We appreciate your patience while we work on it!"

Users began reporting issues with the app on social media this afternoon.

An update from just after 4pm on the company's website reads: We're still working to restore functionality to affected Slack features but have also discovered some workflows may also be experiencing issues.

"We appreciate your patience as we sort this out and will be back with another update soon."

Then, the company followed up just over 20 minutes later with another update: "We're still working to restore functionality to affected Slack features such as sending messages, workflows, threads and other API-related features.

"Users may also experience issues when attempting to log-in. Thank you for your continued patience as we continue investigating. We'll be following up with further updates as they become available."

Slack said it began "investigating" the issue at around 3:30 pm amid reports of people not being able to connect to the app.

Then, roughly 15 minutes later, it said it's "investigation is still ongoing" but managed to pinpoint some of the issues users were facing.

The update read: "Our investigation is still ongoing but have determined a variety of API endpoints, sending/receiving messages, and some threads loading are also impacted. We'll be back with another update as soon as possible."

The last update on Slack's website was issued at 4:30 pm, and people on social media are still reporting issues with the messaging app.