SAN FRANCISCO (AP) — Twitter CEO and co-founder Jack Dorsey says the social media platform accidentally suspended his account.

Dorsey tweeted Tuesday night , "just setting up my twttr.again (account suspension was an internal mistake)." The post was an echo of his first-ever tweet , which came in 2006.

San Francisco-based Twitter suspended the accounts of several prominent members of the so-called "alt-right" in an apparent crackown on accounts tied to hate speech or threats of violence. Twitter declined comment, but noted its policies against hate speech and harassment.

Some supporters of the...