Twitter today launched Twitter Alerts, a new feature that gives users important and accurate information from credible organizations during emergencies, natural disasters, or moments when other communications services aren’t accessible. Currently only organizations in the US, Japan, and Korea can send Alerts, but Twitter says it we will expand the service to include more public institutions and NGOs around the world.

Here’s how it works. First, you have to sign up to receive Twitter Alerts from a given account (so that you only receive relevant information). Once you do, you will receive a notification directly to your phone whenever that account marks a tweet as an alert.

To sign up, you can go directly to an account’s setup page, which you’ll find at twitter.com/[username]/alerts. On Twitter for Web, you can see if an organization is part of the program when you visit its profile.

alerts1 Twitter launches Alerts service in the US, Japan, and Korea to keep users informed during emergencies

Notifications are delivered via SMS, and also appear differently on your home timeline from regular Tweets (they are indicated with an orange bell). If you use Twitter for iPhone or Twitter for Android, you’ll also receive a push notification; you need to be using at least Twitter version 5.10 for iOS or Twitter 4.1.6 for Android.

Twitter Alerts builds on the company’s launch of a service called Lifeline just over a year ago. The feature helps Japanese users input their postal code to find and follow local accounts that are important in crises.

You can see all the participants in a list here. In total, there are 13 national agencies in the US, 10 regions for FEMA, 33 state-specific ones, eight groups in Japan, one organization in Korea, and seven global non-profits.

This is a smart move on Twitter’s part. Many already use the social network during emergencies, so building on that use case can only help the service grow.

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Top Image Credit: Leon Neal/Getty Images