An Egyptian military court has handed down seven death sentences for an April 2015 bombing that killed two army cadets as they waited to board a bus, an army official said.

The blast in the Nile Delta city of Kafr el-Sheikh was one of a spate of attacks that have hit the security forces since the 2013 overthrow of Islamist president Mohamed Morsi.

Most have been in the Sinai Peninsula, but some have been in Cairo or the delta to its north.

The court in second city Alexandria also sentenced five people to life in prison, which in Egypt means 25 years, the army official said.

It sentenced two defendants to 15 years, and four to three years.

The defendants have the right of appeal to the Court of Cassation.

Three of those sentenced to death were tried in absentia.

Police have detained or killed scores of suspected militants in Cairo and the delta, although the security forces continue to face frequent attack in the Sinai, stronghold of jihadists loyal to the Islamic Strate group.

The jihadists say their attacks are in retaliation for a government crackdown targeting Morsi's supporters that has left hundreds dead and thousands imprisoned.

Morsi himself and hundreds of his followers have been handed death sentences, many of them in speedy mass trials that have been condemned by the United Nations and human rights groups.

Some have been overturned by the Court of Cassation on appeal.