Wriggling through crater-sized holes in deserted, bullet-pocked buildings, once-dormant Kurdish militia in Aleppo city are providing Syrian rebels a much-needed boost to push back regime forces.
Since the uprising against President Bashar al-Assad's regime started more than two years ago, Syria's Kurds, who make up 15 percent of the population, have largely refrained from taking sides, keeping both regime and rebel forces out of their neighbourhoods.
But in a momentous development that could potentially change the course of the civil war, the Kurds joined forces with Syrian rebels last month, helping them overrun the strategic Sheikh Maksud neighbourhood on a hilltop north of Aleppo.
Sheikh Maksud is currently in the midst of some of the heaviest fighting since the uprising began, with incessant sniper fire and aerial bombardment in the wake of the newfound alliance forcing thousands of Kurdish residents to flee the district.
"We have the same goal as the rebel fighters," said Engizek, a commander of the People's Protection Committees (YPG), the armed wing of Syria's main Kurdish Democratic Union Party (PYD).
"It is to seek the ouster of Assad," Engizek, who goes by a single name, said in Sheikh Maksud during a lull in fighting interspersed with sporadic bursts of sniper fire but declining to comment on the shift in the Kurdish policy of neutrality.
Syria's largest city Aleppo has been mired in a bloody stalemate as the fighting involving fragmented rebel forces moves slowly from street to street, neighbourhood to neighbourhood, with neither side making major tactical headway.
But militiamen of PYD -- considered to be the Syrian offshoot of Turkey's outlawed Kurdistan Workers' Party (PKK) -- may just provide increasingly desperate rebels a boost to break the deadlock.
"The 'Kurds of Aleppo and north' have preferred to remain neutral when they can, but (they) understand that they must live with Arabs and have no hope of ever gaining an independent state or autonomy," said Joshua Landis, director of the Center for Middle East Studies at the University of Oklahoma.
They "can make a difference" by joining forces with the Free Syrian Army, said Landis.
Since entering Sheikh Maksud, PYD militia, which also included women fighters, have managed to cut off regime supply routes to key positions including a local hospital.
But Kurdish rebels, some as young as 14, who have set up sniper nests in dank, desolate buildings once crowded with civilians, say the regime forces have proved to be stubbornly resistant.
The fighting in Sheikh Maksud has morphed into an urban guerrilla war playing out in slow motion and dominated by snipers.
"This has turned into a sniper's war," said Sawoushka Ahmed, a 17-year-old fighter. "They (regime fighters) are skilled at urban combat. Their night-vision snipers often launch surprise raids at night. We have to remain vigilant round the clock."
Fighters stealthily climb through mouse holes punched in walls -- in order to avoid streets on the target of regime snipers -- and pick their way through shattered furniture and possessions left behind by residents who fled after Assad's forces threatened to bomb the district.
One of the last remaining Kurdish residents was seen ducking down from sniper fire as he hurriedly loaded mattresses in a mini truck outside a shell-ravaged building.
Some Kurdish fighters interviewed by AFP said the decision to realign with Syrian rebels came after weeks of deliberation within the group's top leadership.
Assad's troops pulled out of majority-Kurdish areas in northern Syria last summer, granting the Kurds a partial autonomy apparently in exchange for their remaining neutral in the war.
But the Kurdish combatants interviewed said the uneasy truce with Assad began deteriorating as Sheikh Maksud often came under fire amid raging battles with the rebels.
The alliance came just days after the Kurdish leader Abdullah Ocalan, currently imprisoned in Istanbul, declared a truce with Ankara -- a move that could potentially end the long-running Kurdish insurgency in Turkey.
Observers say that the position of the Syrian Kurdish leadership is likely to be heavily swayed by the way the unprecedented Turkish ceasefire progresses, but the Syrian agreement is already showing signs of strain.
"Some Free Syrian Army (FSA) rebels are seriously fighting for freedom, some are not," said commander Engizek.
"There is no organisation, hardly any unity within the FSA. It's a total mess," she said, without elaborating on how that might impact their newfound alliance.