Twitter has launched a new feature that lets users post tweets that disappear after a day.

The social media company calls the new tweets “fleets.” The word fleet is an adjective meaning very fast or quick. Fleets can be sent as written messages, pictures or videos.

Twitter says it decided to add the feature after some users expressed concerns about the current tweeting system.

Fleets cannot be retweeted and will not have likes. The only way a person can answer or comment on a fleet is by sending the user a direct message. This prevents any back-and-forth communication between users from becoming a public discussion.

The new Twitter feature comes long after other social media services – including Snapchat, Facebook and Instagram – added the ability for users to send disappearing messages. Such messages have become increasingly popular with social media users looking for smaller groups or more private messaging.

However, some Twitter users who experimented with the feature said they were worried that the tool may create new possibilities for online abuse. For example, they said fleets could permit the sending of unwanted direct messages. The feature also permits fleet writers to “tag” people who have blocked them.

A Twitter official told Reuters news agency it was listening to suggestions from users and would work to fix safety concerns like the blocking issue.

Twitter and other social media companies are under pressure to do a better job of preventing abuses and limiting the spread of misinformation on their websites.