The Central Intelligence Agency (CIA), one of the top intelligence-gathering agencies of the US government, has sent out its first tweet on its official Twitter page.

It quickly confirmed in a press release Friday that it has joined social networking sites Twitter and Facebook.

Within two hours of the post, it received around 90,000 retweets and gained 115,000 followers.

The purpose of joining Twitter and Facebook was to help the agency “more directly engage with the public and provide information on CIA’s mission, history and other developments”, CIA director John Brennan said in a statement.

However, the agency will not post spy secrets.

The agency already has an official website, and accounts on YouTube and Flickr, an online photo-sharing website.

CIA has long been following social media, secretly.

The agency’s Open Source Centre monitors millions of tweets and Facebook updates a day and tracks information people publish about themselves on those social media.

Those information are then translated to English and cross-checked with other sources of information, for CIA’s reference.