U.N. chief Ban Ki-moon on Thursday condemned attacks against civilians in Syria, in particular aerial attacks with explosive-packed barrel bombs, Al Arabiya reported
"The Secretary-General is following with deep concern the continued armed escalation in Syria, most deplorably the ongoing aerial attacks and the use of 'barrel bombs' to brutal, devastating effect in populated areas," AFP quoted Ban's spokesman, Martin Nesirky, as saying.
In the past six days of such regime attacks on the city of Aleppo, more than 250 people - including 76 children - have been killed, according to the Syrian Observatory for Human Rights, an NGO.
Nesirky said the U.N. chief "condemns once again the indiscriminate use of any weapon against civilians, in contravention of obligations under international humanitarian and human rights law."
He added: "All civilians must be protected in any situation."
The most recent campaign of bombings, which began Saturday, have sparked a mass exodus from worst-hit parts of the city.
Ban urged all sides to "immediately" work on reducing violence and finding a peaceful resolution to the bloody, three-year conflict.
"The secretary-general reiterates that further violence serves the agendas of those who see military means as the only way forward, at the expense of the Syrian people," Nesirky said.
The Syrian government and rebels, meanwhile, agreed a "pause" in the besieged city of Homs to allow access for humanitarian aid into the city, the United Nations said on Thursday.
The agreement also clears the way for the delivery of essential lifesaving supplies for about 2,500 civilians, U.N. spokesman Farhan Haq told reporters, citing comments from Valerie Amos, the U.N. under-secretary-general for Humanitarian Affairs and Emergency Relief.
Rebel-held Old City areas of central Homs have come under near-daily shelling ever since the army blockaded them in June 2012.
According to Syria's state news agency, "authorities will implement the deal by providing the necessary humanitarian assistance, including food, shelter and medical aid for innocent civilians who leave" the besieged districts.