Over the weekend, Mohamed Morsy cleaned house. Following weeks of deadlock with the Supreme Council of the Armed Forces (SCAF), Egypt's first popularly elected president finally stepped out of the military's shadow, sacking a laundry list of top generals, including Field Marshal Hussein Tantawi, and annulling a controversial military decree that curbed the president's powers.

The surprising political showdown came on the heels of a devastating terrorist attack in el-Arish, North Sinai, on Aug. 5 that left 16 members of the Egyptian security forces dead and the military looking complacent. Morsy pounced on the opportunity, ordering both a shakeup of the armed forces and an all-out offensive in Sinai, pounding supposed militant strongholds with missiles and helicopter gunships -- the first use of such hardware since the 1973 war with Israel.

But if it's clear that the "Ramadan massacre," as it has become known in Egypt, gave Morsy the political space to outmaneuver the generals, what exactly is happening in the Sinai remains something of a mystery. Who was behind the Aug. 5 attack -- and who has borne the brunt of the military's subsequent incursion -- are still open questions.

One soldier who survived the attack blamed "masked men" with a "Palestinian dialect" in an interview after the fact. Others have pointed to "infidels," "elements from the Gaza Strip," and Israel's Mossad. Few seem to have a firm grasp on the facts.

Yet this was not the first time unknown militants have wreaked havoc in Sinai. For years now, Egyptian security forces have been battling a ghost in the desert. Since the 2011 uprising that toppled President Hosni Mubarak, militants have blown up the pipeline that supplies natural gas to Israel 15 times. Only weeks before the Ramadan massacre, gunmen on a motorbike attacked a military outpost in Sheikh Zuweid, leaving two members of the Egyptian military dead.

Yet analysts have struggled to pinpoint the source of the terror. Some flirted with blaming al Qaeda, while others hedged their bets by fingering groups "inspired by al Qaeda." Takfir wal-Hijra, a loosely organized extremist group with roots in Sinai, is also a usual suspect. The organization views most people as infidels -- including Muslims who fail to follow their strict interpretation of Islam -- and adheres to a radical militant ideology that requires them to purify the world of kufar, or heretics. But aside from a handful of attacks that security forces have attributed to Takfir wal-Hijra, there seems to be little consensus about who is to blame for the uptick in violence.

In part, this is because the extremist groups themselves appear to be proliferating -- or at least morphing. Over the past two years, the Internet has been flooded with statements and videos released by unknown groups vowing to create a puritanical Islamic state in Sinai. A statement released two days before last week's attack by a group calling itself Jund al-Sharia ("soldiers of sharia"), for instance, called for a Sinai "emirate" governed by Islamic law and threatened to attack the Egyptian military if it did not release prisoners the group claimed were "falsely" detained. In reality, however, no one has been able to verify the location or reach of these groups -- or even if they exist outside of cyberspace.

Similar mystery shrouds the Ramadan attack, for which no one has yet claimed responsibility. According to an Egyptian general from the border guard intelligence team who spoke on the condition of anonymity, "There is serious intel that those who committed the Sunday massacre are members of Palestinian Islamic Jaljala Army." The Jaljala Army is an extremist offshoot of Hamas based in Gaza, meaning that its members would have had to cross into Sinai via the intricate web of tunnels controlled by Hamas.

Ibrahim Menei, who owns and operates one of the tunnels, also thinks that Hamas, which has condemned the attacks, is at least partially responsible. "Of the hundreds of tunnels used for smuggling, not more than 10 are designed for smuggling humans in and out of Gaza. They are not more than 200 meters long, and no one enters them without paying a minimal fee to Hamas. You can be in Sinai in 15 minutes," Menei explained to me in an interview.

Both the general and Menei, who has built a fortune over the years smuggling weapons, animals, drugs, food, and building materials into Gaza, agree that Palestinian fighters could not have acted alone. As Menei noted, such fighters would have needed the assistance of "bad" Bedouin who provide safe houses, logistics, and on-the-ground intelligence. In other words, radicals on the Egyptian side of the border must also have been involved in the attack.

But the haphazard response by Egyptian officials suggests that they are as in the dark as ever. Following one of the highly publicized raids on the border town of Sheikh Zuweid, Gen. Ahmed Bakr, the head of North Sinai security, announced that the military apprehended six terrorists including Selmi Salama Sweilam, nicknamed "Bin Laden" by Egyptian authorities for his alleged role in numerous terrorist operations. Three of the suspects were released two days later.

A visit to the village in Sheikh Zuweid where Selmi was supposedly apprehended, however, suggests that the raid was a sham -- designed to appease the public and deflect attention away from the military's incompetence. According to Um Suleiman, the wife of "Bin Laden," masked security forces stormed her home early in the morning, beating her viciously and terrorizing her children. The men ransacked the house, broke down the cupboards, and spilled big bags of wheat and barley on the floor.

"They picked up six men who have nothing to do with terrorism, including our 72-year-old neighbor who was feeding his goat at the time, my 20-year-old son, and my ill, 68-year-old husband, whom they called Bin Laden," she said.

Suleiman and her eight children showed off stacks of date boxes, which she insisted were Selmi's only source of income. "We voted for Morsy to escape Mubarak's injustice. Now we don't believe in him! It's the same way they treated us in 2005 after the Dahab and Sharm El Sheikh bombings," Suleiman complained.

The raids in North Sinai have produced other dubious accounts of how the military is prevailing against those responsible for the recent violence. Last Wednesday, the SCAF issued a statement saying that the operation targeting "armed terrorist elements" in Sinai "has accomplished this task with complete success."

That same day, reports leaked by Sinai security officials to dozens of journalists claimed that battles were ongoing in the al-Halal mountain in central Sinai, where security forces were supposedly pounding Islamic insurgents. But not a single Bedouin or journalist was able to confirm these clashes. Journalists have since dubbed the operation "Sinai's Invisible War."

More misinformation came from an overzealous state TV reporter who announced on Wednesday that 20 militants had been killed in the village of el-Touma, in the Sheikh Zuewid district of Sinai. Journalists and Bedouin flocked to the scene and later to the el-Arish hospital, but no bodies were ever located. Residents showed the press parts of two spent rockets and the charred remains of a vehicle, but that was the extent of damage.

Following the report, official security spokesmen who are usually media-friendly went mute and stopped answering their phones. Wire services and other media outlets broadcast the figures globally, announcing that 20 insurgents had been killed. But the initial report was never confirmed. In fact, it was almost certainly false. The journalist who first reported the attack on Nile TV through a phone interview has been exiled from Sinai for more than a year because of his reputation for feeding lies to the media. He actually reported the attack from the city of Fayoum, located in another Egyptian directorate some 260 miles away.

Soon after, the same reporter fed a story to another media outlet about an attack on the United Nations multinational peacekeeping force (MFO) based in Sinai. MFO spokesman Kathleen Riley denied the attack outright, calling it an "inaccurate report."

Al-Ahram, a state owned newspaper, ran a similarly dubious story on Friday, claiming that 60 "terrorists" had been killed in airstrikes. No bodies were ever recovered.

Over the weekend, el-Arish's residents greeted a long convoy of jeeps carrying rocket launchers and M-60 tanks aboard flatbed trucks. Onlookers waved dutifully to the troops as they headed toward the front lines, but they were undoubtedly wondering where this "invisible war" was taking place.