At least 25 policemen were killed in a militant ambush in the border city of Rafah on Monday. Cairo described the attack — the deadliest in recent years — as a plot to “destabilise Egypt and terrify citizens”.

The attack came hours after the interim government said 36 Muslim Brotherhood members died during a botched prison breakout near Cairo, but the Islamist party described it as a “cold-blooded” murder by the security forces.

The two incidents brought forth new challenges for the government as it struggles to deal with a tense standoff with the Brotherhood that has left over 850 people dead since the security forces stormed two camps of supporters of ousted President Mohamed Morsy on August 14.

The supporters of Muslim Brotherhood have been staging demonstrations across the nation demanding reinstatement of Morsy — the country’s first freely elected president — since his removal on July 3 by the army. Rafah, on the border between Egypt and Gaza, is the site of a key border crossing.

Mubarak’s release

Ousted Egyptian dictator Hosni Mubarak could be freed this week after a court on Monday ordered his release pending a probe into a graft case, a development that could further inflame passions in the conflict-ridden and deeply-polarised Arab nation.