EL-ARISH, Egypt -- An Egyptian militant group affiliated with the Islamic State of Iraq and Syria (ISIS) has claimed responsibility for coordinated and simultaneous attacks that struck more than a dozen army and police targets in three towns in the restive Sinai Peninsula, killing at least 26 security officers.
Following the attack, Egyptian President Abdel-Fattah el-Sissi cut short a trip to Ethiopia, to return to Cairo, the state MENA news agency reported Friday.
The wide-ranging attack late Thursday required a previously unseen level of coordination. At least one car bomb was set off outside a military base, while mortars were simultaneously fired at the base, toppling some buildings and leaving soldiers buried under the debris, official said.
In Washington, State Department spokeswoman Jen Psaki expressed U.S. condemnation of the attacks, adding that the "United States remains steadfast in its support of the Egyptian government's efforts to combat the threat of terrorism in Egypt."
An Egyptian army spokesman immediately blamed former hardline Islamic President Mohammed Morsi's Muslim Brotherhood of orchestrating the attack. Twenty-five soldiers and a policeman were among those killed.
Along with the military base that was hit, the other attacks included mortar rounds fired at a hotel, a police club and more than a dozen checkpoints, officials said. The militants struck the Northern Sinai provincial capital el-Arish, the nearby town of Sheik Zuwayid and the town of Rafah bordering Gaza.
Hours before the attack, an ISIS affiliate in Egypt posted on its official Twitter account pictures of masked militants dressed in black. They were carrying rocket-propelled grenades in a show of force, while flying the ISIS black flag.
The militant group later claimed responsibility for the attacks, saying on Twitter that two suicide bombers and three car bombs struck an army base and adjacent security building in el-Arish - the biggest of all attacks.
The posting called it "an extensive simultaneous offensive for the soldiers of the caliphate" and listed at least eight checkpoints that also came under attack in the three locations.
The group, previously known as Ansar Beit al-Maqdis, has launched several attacks against police and the army in Sinai in recent years. It was initially inspired by al-Qaida, but last year, it pledged allegiance to ISIS, which controls large parts of Syria and Iraq. In November, it changed its name to Sinai Province, or Waliyat Sinai, reflecting its loyalty and subordination to ISIS, which has captured a third of both Syria and Iraq.
At least 60 people were wounded in the Thursday attacks, according to medical officials, who also confirmed the death toll. Officials said the death toll was expected to rise. They spoke on condition of anonymity because they were not authorized to speak to the media.
Army Spokesman Ahmed Samir blamed the Muslim Brotherhood group for orchestrating the attacks in a statement posted on his official Facebook page. In a brief statement, he said that because of the "successful strikes" by army and police against terrorist elements in Sinai, militants attacked a number of army and police headquarters using car bombs and mortars. He said that security forces are exchanging gunfire with the militants.
The explosions smashed windows and shook residential areas in el-Arish. Electricity went off across the city.
El-Sissi, the army chief-turned-president who led the ouster of Morsi, has been depicted as by nationalist media as the rescuer of Egypt from Islamic militancy. He led a wide crackdown on the Brotherhood, who staged near daily demonstrations demanding Morsi's reinstatement, imprisoning thousands and killing hundreds in street protests.
In apparent retaliation, militants launched a spate of attacks that ranged from homemade explosive devices to suicide attacks.
The areas where the attacks took place have been under a state of emergency and a curfew since October, when militants killed 31 soldiers in an attack on a checkpoint in Sinai, the deadliest for the military in recent history.
The ISIS affiliate claimed responsibility for that attack in a video posting that showed militants spraying soldiers with bullets and vowing more attacks.
In an attempt to stop weapons smuggling to and from the Gaza Strip, authorities demolished houses and residential buildings located within 500 meters of the border, where a complex network of tunnels had long been used to bring consumer goods, as well as weapons and fighters, to and from the Palestinian territory.
Sinai-based militants have exploited long-held grievances in the impoverished north of the peninsula, where the mainly Bedouin population has complained of neglect by Cairo authorities and where few have benefited from the famed tourist resorts in the more peaceful southern part of Sinai.
The police in northern Sinai largely fled during the 2011 uprising that toppled longtime autocrat Hosni Mubarak, as militants attacked their stations and killed scores of security forces.
Thursday's attacks are expected to cause a great deal of embarrassment to the government and military after nearly a yearlong offensive in Sinai aimed at uprooting Islamic militants.