A British teenager reportedly lost her leg in a suspected suicide bomb attack in northern Cairo.

The bombing, which let more than 20 people injured, was described by the Egyptian interior minister as the “beginning of a new wave of terrorism”.

No one was killed in the attack, the first in the country’s capital since Mohammed Morsi, the Muslim Brotherhood-backed president, was deposed in July.

Among the most seriously injured was Deqa Hassan, 16, a British girl of Somali origin who lived in Brixton but has been at school in Egypt where she lives with her parents.

She was taken to the nearby Nasr Medical Insurance Hospital where her left leg was removed to her knee, the Daily Telegraph reported.

“I was walking with my friend and at the end of the street we heard the sound of an explosion,” she said from her hospital bed.

“I just hit the floor. People were screaming everywhere. It was very scary.

“Eventually two policemen walked up to us. We were screaming for help but they just walked away. It wasn’t human.”

A spokesman for the Foreign & Commonwealth Office said: “We are aware of reports that a British national was injured in the bomb attack and we are urgently looking into it and liaising with the authorities.”

Egyptian activists said they feared a return to the Islamist terror campaigns of the 1990s, in which scores of people including western tourists were killed.