Egypt's state-run news agency says the state prosecutor has referred 12 activists including several prominent bloggers to trial on charges of instigating violence during a March demonstration at the headquarters of the Muslim Brotherhood, the Islamist group from which the president hails.

MENA quoted Prosecutor General Talaat Abdullah on Wednesday as saying that the activists included Alaa Abdel-Fattah, female blogger Nawara Negm and Ahmed Douma, youth leaders who helped spearhead the 2011 revolution that ousted Hosni Mubarak. Douma had received a six-month suspended sentence for insulting the president on Monday.

Abdel-Fattah has previously denied the accusations. The others could not immediately be reached for comment.

Morsi's government accuses its opponents of fueling unrest to undermine his rule. The opposition charges that Morsi and the Brotherhood seek to monopolize power.