A member of Hamas’s naval commando unit defected from the Gaza-based terror organization nearly a year ago to join the Sinai Province — the Islamic State group’s branch in the Sinai Peninsula, Palestinian sources told The Times of Israel.

Abed al-Wahad Abu Aadara, 20, from the city of Rafah in the southern Gaza Strip, was arrested approximately two months ago by Hamas while visiting Gaza due to his affiliation with IS. He has since been freed.

Although Abu Aadara is not the first Hamas operative to defect to IS, he is the first known member of the group’s naval commando unit to join its ranks.

The weeks following Abu Aadara’s arrest were marked by a dramatic increase in tensions between Hamas and IS, due in large part to the arrest of Gaza-based operatives identified with the group, as well as the reduction in the volume of goods being smuggled to the Gaza Strip from Sinai, which IS used as a means of pressuring Hamas in response to the arrests.

However, due to the recent rapprochement between the two groups, in particular relating to smuggling from the Sinai Peninsula to the Gaza Strip, Abu Aadara has now been released from one of Hamas’s prisons in Gaza.

Hamas naval commandos, seen in a still image from a propaganda video released by the terror group during Israel's Operation Protective Edge, in the summer of 2014. (Screen capture)

Hamas naval commandos, seen in a still image from a propaganda video released by the terror group during Israel’s Operation Protective Edge, in the summer of 2014. (Screen capture)

Abu Aadara began his career with Hamas as a member of the group’s elite Nukhba unit and was later selected as a naval commando.

Abu Aadara’s brother, Mufleh, also joined IS after leaving the Gaza Strip for the Sinai Peninsula over a year and a half ago. He was later killed in Sinai, likely while fighting against the Egyptian army.

Following his brother’s death, Abu Aadara decided to follow in his footsteps by joining IS, crossing the border into Sinai last March.

In recent years Hamas has lost dozens of members of its military wing — the Izz ad-Din al-Qassam Brigades — to IS’s Sinai Province, including a number of its fighters from the elite Nukhba unit. Many of these operatives left for Sinai with their families and relatives and now serve as the Sinai Province’s main points of contact with Hamas. These defectors include a number of Hamas’s experts on operating anti-tank missiles and assembling roadside bombs, who have provided substantial assistance to IS in its war against the Egyptian army.

Islamic State's affiliate Sinai Province at weapons training, February 6, 2016. (Telegram.me/HaiAlaElJehad5 via MEMRI)

Islamic State’s affiliate Sinai Province at weapons training, February 6, 2016. (Telegram.me/HaiAlaElJehad5 via MEMRI)

Abed al-Hila al-Qishta, a former senior member of the Izz ad-Din al-Qassam Brigades before joining IS, was killed in December in an airstrike carried out against IS targets in Sinai, while Abu Malek Abu Shwiesh, who was a top assistant to the commander of Hamas’s military wing in the Rafah area, also reportedly defected to the Sinai Province.

Despite the apparent trend of Hamas operatives leaving the group in favor of IS, the terror organization continues to cooperate with the Sinai Province, in particular in relation to smuggling from Sinai into Gaza. The leadership of Hamas’s military wing in the Rafah area is responsible for coordinating cooperation between Hamas and the Sinai Province in a number of areas, including on weapons smuggling and bringing injured IS operatives into Gaza for medical care.

Although the Egyptian regime is fervently opposed to the cooperation between the two groups, it has taken steps towards reconciliation with Hamas. Just last week, a delegation of Hamas security officials visited Cairo for a series of meetings. The Hamas contingent was led by the deputy commander of the Izz ad-Din al-Qassam Brigades Marwan Issa, considered the de facto chief of staff of Hamas’s military wing in light of the health troubles of current military head Muhammed Deif.