Syrian forces prepare for large-scale Aleppo offensive

The Syrian military is reportedly readying for an assault on the city of Aleppo.

"The large scale operation to wipe out the militancy in Aleppo province is expected to start in the next ten days," Syrian military sources cited by Iran's Fars news said on Thursday. "Fresh recruits in large groups are heading to Aleppo from the coastal province of Latakia."

As many as 10,000 Syrian soldiers arrived in the Aleppo region on Thursday to assist in the upcoming offensive.

Jabhat al-Nusra has come to control large parts of Aleppo, the group isn't part of the collapsing Syrian truce meaning that the Russians and Syrians could technically launch a large-scale offensive against it without violating the terms of that truce.

"It is primarily al-Nusra who holds Aleppo, and of course, al-Nusra is not part of the cessation of hostilities," explained a US spokesman. "So it's complicated. We're watching it."

The Russians are likely to give close air support to any Syrian ground offensive into Aleppo using the advanced Ka-52 and Mi-28 helicopter gunships which remained in Syria following the withdrawal of many of its attack planes in mid-March.

The Syrian build-up comes shortly after airstrikes, which began on Wednesday night, struck the Doctors Without Borders (MSF) supported al-Quds field hospital in Aleppo killing up to 27 people, 14 of whom were doctors and patients.

The head of the UN humanitarian assistance to Syria, Jan Egeland, subsequently warned of "the catastrophic deterioration in Aleppo over the last 24-48 hours."

"No one doubts the severity of the situation," Egeland said. "I could not in any way express how high the stakes are for the next hours and days."

"So many humanitarian health workers and relief workers are being bombed, killed, maimed at the moment that the whole lifeline to millions of people is now also at stake."