Egyptian security forces killed nine armed members of the outlawed Muslim Brotherhood in a raid on a Cairo home on Friday, security officials said.

"The Brotherhood members clashed with security forces," said one of the officials, adding that they were meeting to plan what he called "terrorist attacks".

The Brotherhood, which was removed from power by the army in 2013, has accused authorities in the Arab world's largest state of killing members it says were unarmed in similar operations.

In July, the Brotherhood called for a revolt after police killed 13 prominent members in a swoop on an apartment in the Cairo suburb of the 6th of October. The men's families and lawyers said they were unarmed.

Among the dead in that raid was Nasser al-Hafi, a prominent lawyer for the Brotherhood and a former lawmaker. Egypt's Interior Ministry said the 13 men were plotting attacks.

Egypt cracked down on after then-army chief Abdel Fattah al-Sisi toppled democratically-elected President Mohamed Mursi of the Brotherhood after mass protests against his rule.

Security forces shot dead hundreds at a Cairo protest camp and arrested thousands of others, drawing widespread criticism from human rights groups.