DUBAI, United Arab Emirates (AP) — An activist says three fellow campaigners have been detained in Bahrain over their protests targeting the tiny island nation's king during a horse show in the United Kingdom.

Sayed Alwadaei, the director of advocacy at the Bahrain Institute for Rights and Democracy, said the arrests happened Saturday. He says those detained include his sister.

The detentions come as activists have been protesting King Hamad bin Isa Al Khalifa's presence at the Royal Windsor Horse Show taking place in Britain. Already, state-run Bahrain News Agency photographs have shown King Hamad there with Queen Elizabeth II and Dubai ruling family members.

Bahrain is in the midst of a major crackdown on dissent, years after its rulers crushed its 2011 Arab Spring protests. Authorities did not immediately respond to a request for comment.