An Egyptian court has sentenced 10 people to death and five others to life in prison for forming a "terrorist cell" to plot attacks on security forces and other institutions.

The state-run MENA news agency said the defendants are affiliated with the now-outlawed Muslim Brotherhood group and are accused of aiming to assault security personnel and state institutions, target Egypt's Christian minority and disrupt public order.

Saturday's verdict comes after consultation with the Grand Mufti, Egypt's top religious authority, over preliminary death sentences handed to the defendants earlier. The consultation is a formality followed by courts in the cases of capital punishment.

MENA says three of the 15 defendants were sentenced in absentia. Life sentences in Egypt are equal to 25 years. All of the sentences are subject to appeal.

Egypt has cracked down on suspected Islamists since the military ousted president Mohamed Morsi of the Muslim Brotherhood in 2013.

Since then, hundreds of Islamists, including Muslim Brotherhood members, have been sentenced to death. The authorities have carried out dozens of executions.

Egypt is gearing up for presidential elections on March 26-28, in which President Abdel-Fattah al-Sissi is virtually certain to win a second term.