Ashura is a major religious observation celebrated by many across Bahrain.
The majority of these religious observations have remained peaceful. The days immediately following Ashura, particularly Fridays, have historically been occasions for violent protests in highly populated areas.
On November 15, through November 17, the Embassy anticipates possible activity to disrupt non-restricted areas to include shopping malls, markets, and areas where large crowds may gather. Avoid these areas.
From US Gov site:
http://photos.state.gov/libraries/bahrain/5/2013PDFfiles/SecurityMessagetoUSCitizens11-13.pdf