Three women were killed and 17 people wounded when an Aleppo hospital was hit by rebel fire on Tuesday, said the Syrian Observatory for Human Rights (SOHR) and Syrian state media.
The SOHR said the al-Dabit Hospital, which is in a government-held part of Aleppo city, had been heavily damaged.
The attack comes just days after the bombing of al-Quds Hospital in Aleppo, which killed at least 27 patients and staff members, and on the same day the United Nations Security Council is due to vote on a resolution aimed at stopping strikes on hospitals.
It is not certain who carried out the al-Quds Hospital airstrike, though most of the strikes carried out in the opposition-held area in east Aleppo have been done by Syrian state or Russian forces.
Speaking after a meeting with UN Syria envoy Staffan da Mistura on Tuesday, Russian Foreign Minister Sergey Lavrov said a cessation of hostilities in Aleppo would be announced "within hours," reported Russia Today.
The UN had previously urged Russia and US to save the crumbling ceasefire across Syria. More than 250 people have been killed in Aleppo in the past 10 days.
The Syrian army said Tuesday's al-Dabit hospital attack was part of a widespread offensive in Aleppo launched by rebel groups, which involved bombarding civilian areas with rockets.
Heavy rebel shelling in government-held areas of Aleppo killed at least 19 people on Tuesday, including three children, and wounded another 80, according to SOHR.
An airstrike south of Aleppo meanwhile killed at least three people, SOHR said.
Fighting also erupted east of Damascus overnight on Tuesday despite a temporary truce announced by the Syrian army in that area, according to the SOHR, and rebel group Jaish al-Islam said it had lost ground to the government there.
Local ceasefires were announced late last week in the Eastern Ghouta area near Damascus and in northern areas of Latakia province. Washington DC and Moscow said on Monday they were working hard to extend the truce to Aleppo.
An opposition activist in northern Latakia told Reuters the area had been completely calm for three days.
Jaish al-Islam said in a statement overnight that government forces had taken ground around the town of al-Marj in Eastern Ghouta. The rebel group said the loss had been made easier because of in-fighting with rival rebel groups.
More than 35 airstrikes also hit Islamic State (IS)'s de facto capital in Syria overnight, killing another 13 people and wounding many in the city of Raqqa, according to SOHR.
The group said it did not know if the planes bombing Raqqa were Russian or belonged to the international coalition led by the United States which is attacking IS in Syria and neighbouring Iraq.
At least five members of the ultra-hardline militant group died in the attacks, the SOHR added.
Russia's ambassador to the United Nations in Geneva was quoted as saying on Friday that Syria's army was planning to attack Raqqa, backed by the Russian Air Force.
An image tweeted by citizen journalism group Raqqa is Being Slaughtered Silently appeared to show the impact of the air strikes in Raqqa.
US Secretary of State John Kerry said on Monday he hoped for more clarity in the next day or so on restoring a wider ceasefire, a reference to a February 27 "cessation of hostilities" agreement that has unravelled in recent weeks, particularly in Aleppo.
Speaking in Geneva after another attempt at talks with UN and Arab diplomats aimed at procuring a real ceasefire he said the Syrian conflict is "in many ways out of control."
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