Rebels in Syria say Aleppo was pounded by a volley of Scud missiles late Monday, killing some 50 people and injuring scores more.
Opposition fighters said five of the high-power long-range ballistic missiles had shelled the city, leaving the rebel-held neighborhood of Jabal Badro in ruins.
The report could not be independently confirmed.
Pictures and video released Tuesday morning showed a large swath of urban area reduced to rubble, with hundreds of people working to dig out bodies.
Fighting between rebels and regime fighters loyal to embattled President Bashar Assad have battled for control of the large northern city for several months, destroying much of what was once the financial center of the country.
The use of ballistic missiles against population centers would mark a new height in fighting as the Syrian civil war nears its third year.
Rebels have been trying for months to capture Aleppo’s international airport, which lies east of the city in a complex with a smaller military airfield and an army base charged with protecting the area.
The base, home to the Syrian army’s 80th Brigade, fell to rebel forces on Wednesday, and fighting has continued over the airports since, with both sides shelling each other’s positions.
The Britain-based Syrian Observatory for Human Rights said Friday that some 150 people had been killed in the fighting over the last two days, roughly half of them rebels and half of them government troops.
“The operation will continue until we control the airport and Nairab,” Col. Abdul-Jabbar al-Aqidi, commander of the rebels’ Military Council in Aleppo, told pan-Arab Al-Arabiya TV.
If the rebels were to capture the two airports, it would be a symbolic blow to the regime and could shift the strategic balance in northern Syria. The regime has used the airports to ferry supplies to its forces bogged down in the stalemated fight for Aleppo, though recent clashes near the airport have halted air traffic.
Rebel leaders hope their forces will someday use the airports to fly in aid and other supplies — a scenario that for the moment appears unlikely.
The rebels have captured military airports before but have never managed to use captured aircraft. And the airport would remain vulnerable to attack by Assad’s air force, which regularly bombs areas after the rebels take them.
This week, rebels seized a hydroelectric dam and a major oil field, cutting off President Bashar Assad’s regime from key resources necessary for its long term survival.
Elsewhere, the Observatory reported on Friday that rebels has seized an air defense base in the village of Hasil, southeast of Aleppo, and were clashing with the army at the nearby Kuwiras air base and around the Wadi al-Deif army base in Idlib province.
The relentless violence has led to deteriorating humanitarian conditions for millions of Syrians.
In Geneva, the UN World Food program said some 40,000 Syrians have fled the northeastern town of Shadadah. Rebels seized the town and most of a nearby oil filed in days of clashes this week.
Most of those who have fled went to the provincial capital of Hassakeh province, which produces most of Syria’s oil.
The United Nations says nearly 70,000 people have been killed since Syria’s crisis started in March, 2011.
Syria’s conflict has posed a dilemma for the international community. While the US and many Arab and European countries have called on Assad to leave power, Russia, China and Iran continue to back the regime. Russia, which has been Syria’s primary arms provider for decades, has said it will continue to fulfill its arms contracts.
On Monday, a meeting of European foreign ministers decided against arming the rebels.
Several EU foreign ministers said, in strong terms, that they opposed sending any more arms into the ravaged country.
However, British Foreign Secretary William Hague indicated that Britain might continue its push to arm the rebels at another meeting in three-months.
“We will have to have that debate at the time, and I think that will depend on whether any political progress is now made in Syria and depend on the continued loss of life which continues on an appalling and unacceptable scale,” Hague said.