Egypt's prosecution on Saturday referred to trial 20 alleged militants from shadowy jihadist group Ajnad Misr, over several attacks in which six policemen and a civilian were killed.
Ajnad Misr (Soldiers of Egypt) is one of the main jihadist groups to have targeted the security forces since the army ousted Islamist president Mohamed Morsi in July last year.
The group has said it was behind several attacks on police in the capital, including the killing of a police general near Cairo University in April.
In June, Ajnad Misr warned it had planted bombs near a Cairo presidential palace. Days later, two police officers were killed defusing them.
Militant groups say their attacks are in retaliation for the government's crackdown on Morsi supporters that has left more than 1,400 people dead since his ouster in July 2013.
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Of the 20 defendants referred to trial, 14 are in custody, including two alleged leaders of the group, a prosecution statement said.
It said investigations after Morsi's ouster showed Ajnad Misr had "planted explosive devices in 20 sites", targeting police installations and police gatherings near a metro station, university and courthouse in Cairo.
Six policemen and one civilian were killed in the attacks, and more than 100 police and civilians were wounded, the prosecution said.
The group has also said it carried out two of four bombings that rocked Cairo on January 24, the day before the third anniversary of an uprising that toppled strongman Hosni Mubarak.
The government says the militants have killed about 500 people, most of them security personnel, since Morsi's ouster.
Most of the attacks have taken place in the northern Sinai Peninsula where the army is battling an Islamist insurgency, but militants have also extended their operations into the Nile Delta and the heart of the capital.