In this Thursday, April 28, 2016 image made from video and posted online from Validated UGC, a man carries a child after airstrikes hit Aleppo, Syria (Photo: AP)
Russia said Tuesday it hoped a new ceasefire could be announced within hours for Syria's battered city of Aleppo, where fresh fighting left at least 16 dead including in rocket fire on a maternity hospital.
As the city was struck by some of its heaviest reported clashes in recent days, Russian Foreign Minister Sergei Lavrov said efforts were underway to agree a freeze in the fighting.
"I am hoping that in the near future, maybe even in the next few hours, such a decision will be announced," Lavrov told reporters after talks with the UN's Syria envoy Staffan de Mistura in Moscow.
World powers have been making a concerted push this week to stop the fighting in Aleppo and salvage a landmark ceasefire agreed in late February.
The truce between President Bashar al-Assad's regime and non-jihadist rebel forces raised hopes for efforts to finally resolve Syria's five-year conflict. But it has all but collapsed amid renewed fighting, especially in Aleppo.
A surge of violence that erupted on April 22 has left more than 270 people dead in the divided northern city and undermined efforts to revive peace negotiations.
After a relative lull in clashes on Monday and early Tuesday, rebels in eastern Aleppo fired a barrage of at least 65 rockets into government-controlled neighbourhoods, Syrian state news agency SANA reported.
At least three women were killed when the rockets crashed into a maternity hospital, the agency and state television said, and another 11 killed in fire on other government-held neighbourhoods.
The Syrian Observatory for Human Rights, a monitoring group, said it had counted at least 19 dead and 80 wounded from the attacks on government neighbourhoods.
An AFP correspondent in the city saw the heavily damaged hospital building towering over the charred remains of a parked car.
Fierce fighting was also raging on the city's western edges after rebel groups detonated explosives in an underground tunnel, the correspondent said.
He described it as the most violent day for the city's regime-held west since clashes resumed 11 days ago.
Fresh regime air strikes also hit rebel-held eastern areas in the afternoon, another AFP correspondent reported.
Rescue workers in the area said at least two people were killed in the strikes.
In Moscow after seeing US Secretary of State John Kerry in Geneva on Monday, De Mistura said it was crucial for the ceasefire to be "brought back on track", hailing the February truce agreement as a "remarkable achievement".
Diplomatic efforts were set to continue with De Mistura joining the foreign ministers of Germany and France for talks with Syria's main opposition leader in Berlin on Wednesday.
Discussions will focus on "how the conditions for a continuation of the peace talks in Geneva can be met, as well as how a reduction of violence and an improvement in the humanitarian situation in Syria can be achieved", the German foreign ministry said in a statement.
On Monday Kerry said the situation in Syria was "in many ways out of control and deeply disturbing."
Washington and Moscow are working together to include Aleppo province in a so-called "regime of silence" -- a freeze in fighting.
The freeze is meant to bolster the broader February 27 truce also brokered by the two world powers.
The two countries have agreed to boost the number of Geneva-based truce monitors to track violations "24 hours a day, seven days a week," Kerry told reporters.
"We're trying to press this as fast as possible but I don't want to make any promises that can't be kept," Kerry told reporters after meeting de Mistura and Saudi Foreign Minister Adel al-Jubeir -- whose government has influence with key rebel groups.
In a nod to Moscow's demands, Kerry said Washington would press moderate rebels to separate themselves from Al-Nusra Front's jihadists in Aleppo.
Russia and Assad's regime have used the presence of Al-Nusra, an affiliate of Al-Qaeda which was not party to the February ceasefire deal, as an excuse to press their offensive.
The Observatory says more than 270 civilians -- including at least 49 children -- have been killed on both sides of divided Aleppo since April 22.
Aleppo city was initially left out of a new deal announced last week to "freeze" fighting along two major fronts in Syria's northwest and in Eastern Ghouta near Damascus.
Syria's conflict erupted in 2011 after anti-government protests were put down, escalating into a multi-faceted war that has killed more than 270,000 people and forced millions from their homes.