Aleppo and Deir al-Zour prepare for new battles

Syrian government forces attacked St Elias Cathedral in Aleppo on Saturday, killing a Catholic priest, Michel Oubaji, who had met with members of rebel group Islamic Front on Easter a couple of days ago.

The attack was followed by regime airstrikes on Sunday that hit a school in a rebel-held area, killing at least nine people, including five children, and wounding dozens.

A statement by the director of education in Aleppo urged schools to close for the rest of the week, as deadly attacks are expected on rebel-held areas.

The bloodshed comes a day after rebel shelling and government airstrikes killed more than 30 people on both sides of the divided city, which is carved into government and rebel-controlled areas.

However, the rebel Artillery Operations Room issued a statement on Sunday condemning groups responsible for shelling civilians in regime-held neighbourhoods.

The Syrian regime mainly controls the west of the city, while rebels control the east. IS is also understood to be preparing for an offensive on rebels in Aleppo.

Last week, two deadly car bombs, allegedly carried out by IS, hit rebel bases in the town of Marea and Hour Kilis, killing tens of civilians including two rebel leaders and wounding dozens more.

Aleppo, Syria's second largest city and its former commercial hub, became a key front in the war after rebels launched an offensive there in July, 2012.

Rebel divisions exposes Aleppo to IS

IS and Assad are exploiting the collapse of the Levant Front in Aleppo, which combined several rebel groups under one banner.

Last year, Aleppo's Islamic Front, The Army of Mujahideen, and others, joined forces to established the Levant Front. The alliance was seen as the most significant among rebels since the beginning of the Syrian uprising.

After strategic victories on the ground, the Levant Front started witnessing major splits.

Most recently, the Nour Movement and al-Huda Brigade, among others, anounced that they were leaving the Levant Front and forming a new alliance, called al-Sham Revolutionaries, under the leadership of Naji al-Mustafa.

The split has led to some tensions and clashes between the Levant Front and the newly formed al-Sham Revolutionaries.

This came as civilians organised protests and voiced their demand for rebels to take greater responsibility towards the deteriorating security situation in Aleppo.

IS leaves Yarmouk to al-Nusra and Ahrar al-Sham

Pierre Krahenbuhl, head of the U.N. agency for Palestinian refugees, known as UNRWA, was meanwhile set to meet with Syrian and U.N. officials in Damascus to discuss the humanitarian situation in Yarmouk camp.

Krahenbuhl met with some 120 Palestinians who have found temporary refuge at a school in the Tadamon neighborhood.

Now relatively safe, the Palestinians recalled the humanitarian crisis inside Yarmouk, where residents have already endured a more than two-year government siege, starvation and disease.

"The conditions were very difficult," said Rahaf Qadri, who left Yarmouk 10 days ago. "There was no food, and diseases have started to spread."

Qadri said her husband is still in the camp, and has joined Palestinian factions trying to protect Yarmouk from the IS incursion.

The agency's spokesperson, Chris Gunness, said in a statement that there are deepening concerns over the safety of some 18,000 Palestinian and Syrian civilians, including 3,500 children, who remain in the camp.

Guinness later wrote on his Twitter account that UNRWA treated 31 Yarmouk evacuees, including two pregnant women, who fled to the nearby neighborhood of Tadamon. He added that the youngest displaced person from the camp is six weeks old.

IS militants overran much of Yarmouk last week, adding to the misery of thousands of Palestinians inside the camp who have been living with a regime-enforced siege for almost two years.

However, sources from inside Yarmouk told al-Araby al-Jadeed on Monday that IS will retreat from the rest of the camp today after handing over more than 90 percent of their positions by Sunday to al-Nusra Front and Ahrar al-Sham.

IS prepares for Deir al-Zour

Both regimes forces and IS are mobilising in prepartion for a major battle in Deir al-Zour.

A defected Syrian officer who is now a member of IS told al-Araby al-Jadeed that IS is concentrating on Deir al-Zour, and the Syrian front more generally, as the group loses ground in Iraq.

IS is now attempting to regain lost momentum, and the officer confirmed to al-Araby al-Jadeed that IS are mobilising on the outskirts of Deir al-Zour, mainly in the towns of al-Mayadeen, al-Jneyneh, and al-Hasan.

The group has also been preparing for the battle through digging tunnels that are 8 meters deep and 4 meters wide in the towns under its control around Deir al-Zour, the defected officer explained.

In return, the Syrian regime is mobilising Iranian-backed militias in the towns of Tadmour and al-Sakhnah, while being surrounded in Deir al-Zour by IS.

The fighters pushed back in Iraq by the Iraqi military, with the support of American airforce and Iranian fighters, are joining the battlefronts in Syria, mainly in Aleppo and Deir al-Zour, and consequently fueling a war that is taking its toll on civilians.