The Syrian opposition has accused the government of committing war crimes on civilians in the city of Aleppo, as the death toll from more than a week of escalating violence continues to rise.
Government warplanes and helicopter gunships launched new air strikes on Saturday on rebel-held neighbourhoods in the northern city.
Speaking after a Syrian National Coalition meeting in Istanbul, Turkey, Anas al-Abdeh, the group's leader, said: "Aleppo has been reeling under intense, ferocious bombardment. It is a systematic campaign. Therefore our meeting today focused on the situation in the besieged area, including Aleppo city.
"It is clear that the regime's uninterrupted shelling and air strikes amount to war crimes and crimes against humanity.
"They attacked medical facilities, residential areas and a bakery catering to more than 300 families."
The fresh violence comes as the International Committee of the Red Cross (ICRC) says the intensification of fighting brings millions of people closer to a humanitarian disaster.
Aleppo is not part of temporary, partial ceasefire which is now in place in the Damascus countryside and Latakia.
The temporary truce appears to be largely holding.
Speaking to Al Jazeera, Louay Safi, former Syrian opposition leader, said there was no internationally agreed plan for the current truce.
"There is an all-out war on Aleppo. The intensity of bombing is very high - they are hitting water facilities, public facilities ... the regime hasn't spared anybody.
"A large number of people have been killed in Aleppo and many of those who have been hurt are elderly and children. They are targeting residential areas, using barrel bombs which are indiscriminate."
Aleppo, Syria's largest city and former commercial centre, has been the scene of intense shelling and air raids over the past nine days that killed nearly 250 civilians, according to the Britain-based Syrian Observatory for Human Rights.
The surge in fighting has caused the collapse of a two-month ceasefire brokered by the US and Russia. It also has raised fears of an all-out government assault on Aleppo.
Medical facilities hit
The ICRC statement issued late on Friday said four medical facilities on both sides of the city were hit earlier that day, including a dialysis centre and a cardiac hospital.
The ICRC appealed to all parties in the conflict "for an immediate halt in the attacks".
"There can be no justification for these appalling acts of violence deliberately targeting hospitals and clinics, which are strictly prohibited under international humanitarian law," said Marianne Gasser, head of the ICRC in Syria.
|Aleppo, Syria's largest city and former commercial hub, is not part of a temporary, partial ceasefire effective elsewhere [Al Jazeera]
"People keep dying in these attacks. There is no safe place anymore in Aleppo.
"For the sake of people in Aleppo, we call for all to stop this indiscriminate violence," Gasser said.
Friday's attacks on the medical centres came after government air strikes damaged a main hospital supported by Doctors Without Borders late on Wednesday.
Those attacks killed more than 50 people, according to the international aid group.
The ICRC said it has warned that because of the intensification of fighting in recent days, millions of people "are facing humanitarian disaster as it becomes increasingly difficult to reach them with aid".
The Syrian Observatory and the Local Coordination Committees reported more than 20 separate air raids on rebel-held parts of the city where an estimated 250,000 people remain.
Aleppo was excluded from a brief ceasefire declared by the Syrian army on Friday.
The truce went into effect after midnight on Saturday in Damascus and its suburbs as well as the coastal province of Latakia.
Activists said both areas included in the truce were relatively calm on Saturday.
In Damascus, Pawel Krzysiek, ICRC spokesperson, said that despite the difficult situation in Aleppo that affects humanitarian operations in the city, work elsewhere was continuing.
Two humanitarian convoys were on the way to two separate areas besieged by rebels and government forces respectively, he said.
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The convoys, a joint operation between the ICRC, UN and the Syrian Arab Red Crescent, will deliver aid to Madaya and Zabadani - two mountain resorts near Damascus that have been besieged by government forces.
Krzysiek said 20 other trucks were on their way to the northwestern villages of Fouaa and Kefraya, which are besieged by rebels.
The ICRC delivers food parcels and wheat flour, medicines, bed nets, crutches and anti-lice shampoo to all locations, he said.
Source: Al Jazeera and agencies