The Egyptian army recently stormed Jabal al-Halal in central Sinai as part of a months-long operation to rid the area of extremists.
The mountainous region, roughly 60 kilometres south of al-Arish, has been a hotbed for extremist groups, and for "Islamic State of Iraq and the Levant" (ISIL) affiliate Wilayat Sinai in particular, experts told Al-Mashareq.
Militants entrenched in the area have taken advantage of its mountains, caves and valleys to establish a stronghold from which they stage attacks.
The Egyptian army said it has seized control of the mountain and of weapons and drug depots, military vehicles, advanced communications equipment and explosives it discovered in the area.
"The Jabal al-Halal storming operation began several months ago, with the cordoning off and encirclement of the area from all sides and closure of all mountain roads and passes," said military analyst Maj. Gen. Abdul Karim Ahmed, a retired Egyptian officer.
"The actual storming operations began in late February, and the sweep operations and raids went on for at least 15 days and are still ongoing, with the aim of gaining full control of the area," he told Al-Mashareq.
It was "a surprise operation carried out in the winter", he said -- a time when "most armies avoid engaging in battles or storming operations because of the poor visibility, difficulty of movement and bitter cold".
The storming of the mountain, 1,700 metres above sea level, is a "knockout blow to the terrorists in Sinai, as it is a major redoubt for them", he said.
In addition to the capture of operations rooms, shelters and vehicle storehouses, documents seized in the raids reveal the militants' movements and plans, he said, and will provide insight into their methodology and potential targets.
The operation to drive extremist elements from Jabal al-Halal has been one of "the most complex and difficult military operations" for the army, said security expert Brig. Gen. Khaled Okasha, who is retired from the Egyptian military.
This is due to the mountain’s rugged terrain, which allows extremists to hide and shelter in fortified positions for long periods of time, he told Al-Mashareq.
He said he expects the sweep will take a long time to complete due to the complexity of the operations, the abundance of caves that serve as hiding places, and mines and booby traps planted by extremists.
'Clear impact' on civilian population
The operation has had a "clear impact" on the situation in populated civilian areas of Sinai, said Maj. Gen. Jawdat Ashraf of the Egyptian police, who is stationed in Sinai.
This is especially the case in the North Sinai provincial capital of al-Arish, he said, where the number of terrorist attacks dropped to its lowest level in years.
"The mountain is the terrorists’ main planning centre," he said, adding that the operation succeeded in scattering them and depriving them of a safe haven to which they could return after carrying out their attacks.
The areas between the mountain and populated areas, particularly around Sheikh Zuweid, al-Arish and Rafah have largely been cleared of the hideouts they used, Ashraf said.
"The storming of the mountain led to the discovery of evidence that revealed the smuggling routes used by the militants and roads they use to infiltrate into Egyptian territory," he said.
The success of the recent crackdown in central Sinai also has had a positive impact on the situation of the area's Coptic population, Ashraf said.
Many Copts fled the peninsula following a series of attacks targeting their community , but a number have since returned to their homes in light of the improved security situation, he said.
The operation succeeded in stemming migration from the area towards cities such as al-Ismailiya, he said, noting that the ministers of defence and interior also visited and toured the city of al-Arish to reassure residents.
Local tribes help security forces
"Jabal al-Halal is a no-go area for the people of Sinai because it is controlled by terrorists who prevent civilians from approaching," said secondary school teacher Mamoun Majeed, a native of North Sinai.
The area has traditionally been used as pastureland, he told Al-Mashareq, adding that there also are olive groves and fruit trees that are currently abandoned because extremists have blocked access to the local population.
Since the uptick in violence began in 2004, militants have taken refuge on the mountain and settled there, he said.
Egyptian police launched several operations to pursue them, but the roughness of the terrain and the large number of passes and gorges in the areas, some of which are 300 metres deep, severely limited their effectiveness, he said.
This has not been the case with the current operation, he said.
"The Jabal al-Halal area is controlled by the Tarabeen and al-Tayaha tribesmen, who provided critical information about the routes, passes and hideouts in the mountain that only they know," he said.