Woman beaten by Egyptian troops in Tahrir Square
20 December 2011 Last updated at 12:49 GMT
Washington has described the treatment of female protesters in Egypt as "shocking" and a "disgrace" after footage emerged of troops ripping off a woman's clothing and beating her.
Clashes between security forces and demonstrators demanding an immediate end to military rule, are continuing in the capital Cairo, overshadowing parliamentary elections which are taking place.
At least thirteen people have been killed since Friday.
Rupert Wingfield-Hayes reports from Cairo.