Air strikes on rebel-held neighbourhoods in Syria's second city Aleppo on Friday killed at least 18 civilians and wounded more than a dozen, the local civil defence told AFP.
The Syrian Observatory for Human Rights said regime warplanes carried out the air strikes and gave a toll of 19 dead, up from its earlier toll of 10.
An AFP correspondent in the opposition-held eastern part of the city said several districts were targeted and that the wail of ambulances could be heard throughout the morning.
Seven civilians were killed and 10 wounded in Bustan al-Qasr, a civil defence member said, and four were killed in Al-Mashad.
The strikes killed five civilians in the opposition-held Salhin district and two more in other neighbourhoods.
In Bustan al-Qasr, one of Aleppo's most heavily populated neighbourhoods, a strike hit a five-storey apartment building, shearing off part of an entire floor.
"We were sleeping at 10:00 am when the strike hit the fourth floor of the building," said resident Ahmad Radi.
"We ran down and found the bodies all over the ground."
Civil defence volunteers were climbing into the building to search for families trapped in the rubble, the AFP journalist said.
Some emerged carrying squirming infants blanketed in dust, while others held limp bodies covered in white sheets.
"It's become normal here for people to die every day. No one even mourns anymore," one Bustan al-Qasr resident said.
"The next day, everyone opens their shops and things carry on as if nothing happened. But everyone living here has lost someone."
"A surprising number of wounded showed up at the field hospital, around 20 people," one medic in an opposition-held neighbourhood told AFP.
"It's more than we can handle," he said, adding that field hospitals in other neighbourhoods were also struggling to cope.
The Britain-based Observatory said a total of 14 air strikes had targeted Bustan al-Qasr and other Aleppo neighbourhoods.
It said they killed 19 people and wounded dozens more.
"The number of martyrs is expected to rise because many of those wounded are in critical condition," said the monitor, which relies on a network of sources inside Syria for its reports.
Once Syria's commercial hub, Aleppo has been divided between rebel control in the east and government forces in the west since 2012.
Nearly all warring parties in Syria -- the regime, rebels, jihadists and Kurds -- have carved out zones of control in war-torn Aleppo province.
A ceasefire took effect in Syria at the end of February, but the country has been rocked by fighting in recent weeks, particularly around Aleppo.
On Sunday, at least six civilians were killed in government strikes on eastern parts of the city, and another 16 were killed by Islamist rebel rocket fire.
Syria's conflict erupted in March 2011 with anti-government protests, but has since spiralled into a multi-front war that has left more than 270,000 people dead.