U.N. Appeals for Urgent Aid Access to Syria's Aleppo

The United Nations has called for urgent aid access to Syria's Aleppo, warning civilians are at grave risk including from severe water shortages after fighting intensified for the city.

Fears are growing for trapped civilians ahead of what is expected to be an all-out battle for control of Aleppo, Syria's second city and a focal point of the country's five-year civil war.

Rebel factions and President Bashar Assad's regime have sent hundreds of reinforcements to Aleppo in anticipation of the fighting, after opposition forces broke a government siege at the weekend and vowed to capture the entire city.

Hundreds of thousands of civilians remain inside the city, once Syria's main economic hub, and U.N. officials sounded the alarm.

U.N. agencies said Tuesday that up to two million people in Aleppo had gone without running water for four days, raising the risks of disease in a city already devastated by years of fighting.

UNICEF said children and families were facing "a catastrophic situation" after fighting damaged electricity networks needed to pump water.

"These cuts are coming amid a heatwave, putting children at a grave risk of waterborne diseases," said Hanaa Singer, its representative in Syria.

"Getting clean water running again cannot wait for the fighting to stop. Children's lives are in serious danger."

The U.N.'s top humanitarian official in Syria, Yacoub El Hillo, and regional coordinator Kevin Kennedy said medical and food stocks "are running dangerously low."

"At a minimum, the U.N. requires a full-fledged ceasefire or weekly 48-hour humanitarian pauses to reach the millions of people in need throughout Aleppo and replenish the food and medicine stocks," they said.

- 'Cut off' -

Aleppo has been divided between a rebel-held east and regime-controlled west since fighting erupted in the city in mid-2012.

The U.N. says two million people in the city are at risk, including up to 275,000 people in east Aleppo. Other estimates put the total number of civilians in the city at about 1.5 million, with 250,000 in the eastern districts.

Jens Laerke, spokesman for the U.N. humanitarian agency, said the situation was "critical."

"Our concern today is really for the entire city... where we have up to two million people who may be cut off from water and electricity," he said in Geneva.

The recent flare-up in fighting began in late June as government forces closed in on the Castello Road, the last route into rebel-held parts of the city.

The road was severed in mid-July, beginning a roughly three-week siege of eastern districts until opposition fighters broke through on Saturday.

The push saw a coalition of rebels, Islamists, and jihadists cut off the regime's own main access road on the city's southern edges.

The offensives have left residents reeling from skyrocketing prices and food shortages and afraid of further violence.

Each side has used newly acquired territory to bring food and other supplies into neighborhoods they control, but the roads are still not safe for civilians to use.

Emboldened by their recent win, the rebel alliance announced an ambitious bid to capture all of Aleppo city, which if successful would mark the biggest opposition victory yet in Syria's conflict.

- 'Mother of All Battles' -

"The battle for Aleppo is arguably the most emotive and strategic of any across Syria," Charles Lister, senior fellow at the Middle East Institute, wrote in an online analysis titled "Aleppo -- The Mother of All Battles".

"Although an opposition conquest of the whole city appears highly unlikely, breaking the siege has sent a powerful message of opposition indefatigability."

Sporadic clashes hit the city's outskirts Tuesday, but there were no signs of either side launching a large-scale offensive.

Yasser Abdulrahim, a rebel commander who leads a joint operations room for Aleppan fighters, said preparations were still underway.

"The big battle has not started yet," Abdulrahim told AFP. "We are waiting for more reinforcements before it begins, and we are trying to find the weakest points in our enemy's lines."

Clashes were taking place in the southern suburbs, in the key district of Ramussa and a collection of military academies.

"Most of the clashes in Ramussa are taking place against Hizbullah and Iranian fighters," Abdulrahim said, referring to Assad's backers in the Lebanese Shiite movement and Tehran.

The Syrian Observatory for Human Rights monitor also said there were clashes in Ramussa, adding that strikes on a rebel-held district killed nine civilians Tuesday.

Syria's conflict broke out in March 2011 with anti-regime protests, evolving into a multi-front war that has left more than 290,000 people dead and millions forced from their homes.