Egypt's military has launched an air strike in North Sinai against Islamist insurgents. Meanwhile, the state prosecutor has brought new charges against ousted President Morsi for allegedly insulting the judiciary.
Egyptian helicopters attacked militant outposts in Sheikh Zuweid and Rafah on Saturday in a bid to uproot Islamist militants. The towns lie along the Sinai Peninsula's border with Gaza.
Nine militants were killed in the raid, according to security officials.
The offensive came as part of a larger "war on terror" in the region. Since the ouster of President Mohammed Morsi in early July, the military-backed interim government has worked to disrupt Islamist strongholds on the peninsula, which offers those groups vast swathes of isolated land, convenient for launching attacks against Egypt and Israel.
Attacks against the Egyptian military have also increased with the political turmoil threatening the country's stability.
Earlier on Saturday, military experts were called to defuse explosives found on the railroad line linking the cities of Suez and Ismailia, which lie to the west of the Sinai Peninsula.
An explosion occurred hours later at a Cairo police station. No injuries were reported, according to state media. Some reports suggested an unidentified assailant had detonated a grenade and not a bomb.
The upswing in clashes between Egyptians security forces and militants came two days after an assassination attempt on Egyptian Interior Minister Mohamed Ibrahim as he was leaving his home for work. One person died in the bombing, but Ibrahim survived unharmed.
Morsi charged for 2005 incident
Meanwhile, Egypt's state prosecutor extended ousted President Morsi's detention over allegations stemming from 2005. The former leader allegedly insulted the country's judiciary by accusing it of rigging polls, thereby placing Islamist group the Muslim Brotherhood at a disadvantage.
Morsi has not been seen by the public since the military removed him from power on July 3. His supporters, mainly comprised of Muslim Brotherhood members, have staged numerous protests and sit-ins calling for his reinstatement as Egypt's democratically-elected leader.
However, the interim government has rejected these calls, vowing instead to oversee fresh elections with the help of the military. It has also brought charges against Morsi for allegedly inciting violence against protesters in December 2012.
kms/jm (AP, AFP, Reuters, dpa)