Bahraini authorities said Thursday that four cyberactivists have been arrested for posting insults about companions of Prophet Mohammed on Instagram.

The four are accused of posting on the smartphone photo-sharing service "texts and pictures damaging to companions of the (Muslim) Prophet", state news agency BNA reported.

It said they were arrested after an investigation of users of the Instagram account and would be put on trial, without identifying the suspects.

The companions of Prophet Mohammed are revered by Sunni Muslims.

Bahrain has been deeply divided since a 2011 uprising led by its Shiite majority against its Sunni monarchy, which brutally crushed the revolt.