Syrian army presses Aleppo campaign as rebels retrench

AMMAN/BEIRUT (Reuters) - The Syrian army and its allies, backed by Russian air power, are keeping up a heavy bombardment of insurgent positions in and around Aleppo, rebels said on Monday, pressing to complete their recapture of the city's strategic southern gateway. After re-imposing a siege on rebel-held eastern Aleppo with an advance in the city's southwest on Sunday, the army and its allies now aim to block the insurgents from bringing in reinforcements, a Syrian military source said. The city, Syria's largest before the war, has become the most important front for both Syrian President Bashar al-Assad and his allies and for the rebels seeking to bring him down. The battle is complicating efforts to establish a ceasefire in Syria, more than five years after the country's civil war broke out. Russia and the United States said on Monday talks on a truce continued, although U.S. President Barack Obama said they "haven't yet closed the gaps" separating them. But Syria's Assad is relying on Russian airpower in its Aleppo campaign, while the United States backs the rebels - or some of them - who are trying to overthrow him. A ceasefire agreed in February collapsed as Washington accused Assad's forces of violating the truce. The latest fighting centers on a military complex at Ramousah that the rebels captured last month after an advance by insurgent groups from Idlib, 55km (34 miles) to the southwest. Their capture of the complex broke a month-long siege of rebel-held east Aleppo, a siege that is resuming as the government forces reassert control of the area. The military source said the army and its allies were working to widen their control near Ramousah's military colleges. "Now the army's belt of control is being widened," the military source told Reuters. "All positions where terrorists are located to the west of Aleppo and south of it are being attacked, because this area is a priority for the army, given that Idlib is the human resources store (for the rebels)." A rebel commander from the powerful Ahrar-al-Sham group said fighters had pulled back to new defense lines to reduce losses in the face of heavy artillery shelling and aerial bombardment. "The Russians have intensified their bombing. We decided to retreat," said Abu Omar, adding his fighters were digging in on new defense lines that would allow them to ambush troops. ESCALATING BOMBING Even before Sunday's advance, the army's capture two weeks ago of the Tal Um Qaraa hilltop had disrupted the rebel corridor into eastern Aleppo, stopping large shipments of essential supplies, two council members in insurgent-held districts said. "They fired at civilians and anything that moved. This led to slower traffic, but after their gains yesterday traffic is completely paralyzed," said Mohammed Aref al-Sharfi, a member of the opposition-run Aleppo Province's local council. Prices inside rebel-held parts of the city have gone up ten-fold, with no new supplies brought in for 12 days because of Russian air strikes and Syrian army bombardments, said Brita Hagi Hassan, president of the city council for eastern Aleppo. Escalating Russian bombing of their supply lines from Idlib, the source of most opposition reinforcements, had exposed rebel positions in Ramousah, where they are still entrenched, two insurgents there said. An operation in northern Syria backed by Turkey, meant to drive out Islamic State and Kurdish fighters from border areas, may also have diverted fighters who would otherwise have been defending Aleppo, some rebels said. Syrian state television throughout Monday broadcast grisly footage showing the mangled, dust-smeared remains of rebel fighters around southwest Aleppo, and of the rubble-strewn districts captured by the army. However, rebels said the Jaish al-Fateh coalition of mostly Islamist insurgent groups was preparing to counter-attack and that reinforcements were arriving for what they predicted would be a protracted battle. On Monday, there was a large suicide bombing and fighting in a government-held part of al-Amariya district north of Ramousah, where rebels said they had advanced into several buildings and supporters of the army said it had repulsed an attack. "The Syrian regime knows the language of force and with its jets uses scorched-earth bombing so its troops then advance and take territory. But can they hold on to it?" said Abu Abdullah al-Shami, a rebel from the Failaq al-Sham group. (Reporting by Suleiman al-Khalidi, Tom Perry and Laila Bassam; Editing by Angus McDowall, Alison Williams and Larry King)