The purported leader of a militant group that has staged several small attacks over the past year in the Egyptian capital has urged holy war, or jihad, calling on the young to join the extremists' fight.

The call came in an hour-long interview with a man identified as Magd Eddin al-Masri, who claims to be the leader of Ajnad Misr, or Egypt's Soldiers, a group that surfaced as part of a rising insurgency in Egypt following the ousting of Islamist president Mohammed Morsi in July 2013.

The interview by the group's media arm was posted on social networking sites.

It was the first public appearance of al-Masri, which is Arabic for "the Egyptian", and a move apparently aimed at gaining more prominence in the group's campaign of retribution for the government's crackdown on Islamists.

In the footage, al-Masri claimed that Egypt is well suited for jihad to avenge the killings, torture and detentions of Islamists in the wake of the authorities' crackdown on Islamists following Mr Morsi's ousting. The crackdown has killed hundreds and jailed thousands.

His group is less prominent than the Sinai-based Ansar Beit al-Maqdis, which has pledged allegiance to the Islamic State and which has claimed scores of large-scale deadly attacks in Egypt.

Ajnad Misr has claimed responsibility for several smaller attacks - including ones that targeted the presidential palace, the foreign ministry and the main Cairo University last year.

Most of the attacks by Ajnad Misr have used rudimentary devices and home-made bombs. Al-Masri said his group's aim is to target security forces, not civilians, and insisted it has no links to any other groups, either in or outside Egypt.

"Jihad in Egypt is an obligation," he said, urging young Muslims to join the fight to avenge "the killing of our men, the dragging of our women and the imprisoning of our youth".

He said that his group had cancelled several planned attacks for fear of killing civilians and added that there are no foreign fighters in the ranks of Ajnad Misr.