File picture: Sue Ogrocki/AP

Cairo - Egyptian authorities have executed nine people convicted in the 2015 killing of the country's top prosecutor, a security source said.

The executions were carried out on Wednesday morning in a Cairo prison after court rulings against the nine became final, according to the source at the Interior Ministry, which is in charge of prisons in Egypt.

Six of those executed were university students when arrested, according to private Egyptian newspaper al-Watan.

After the executions, the bodies were carried to a morgue in Cairo where they will be handed over to their families, the Interior Ministry source said.

The nine people were put to death a day after rights group Amnesty International had called on Egypt to halt the executions.

Later Wednesday, the London-based watchdog condemned the use of the death penalty.

"By carrying out the executions of these nine men today Egypt has demonstrated an absolute disregard for the right to life," Najia Bounaim, Amnesty's North Africa campaign director, said in a statement.

She added that the nine were convicted in trials "marred by torture allegations."

In November, Egypt's top appeals court confirmed death sentences for the nine people convicted in the June 2015 murder of the country's chief prosecutor at the time, Hesham Barakat.

Nineteen others were given varying jail terms in the same case.

Barakat was killed in a car bombing near his house in Cairo.

He was the most senior Egyptian official to die in a spate of attacks following the military's 2013 ouster of the democratically elected but divisive Islamist president Mohammed Morsi following mass protests against his rule.

Most of the attacks have taken place in the northern part of the Sinai Peninsula, but they have crept into the capital Cairo.

They have mainly targeted security forces and Egypt's minority Christians.

Several Islamists, convicted in different cases of violence, have been put to death in Egypt in recent months.

Earlier this month, three people were executed for the killing of a senior police officer during a raid on an Islamist stronghold in the city of Giza near Cairo in 2013.

Last year, four Islamists were executed after they were convicted of murdering military academy students in a 2015 attack in the Nile Delta province of Kafr al-Sheikh.