Syrian rebels Tuesday shelled government-held areas of Aleppo killing 14 people, according to state media, while Syria's ally Russia suggested a ceasefire in the northern city could be reached within hours.
Russian Foreign Minister Sergei Lavrov, who met UN Syria envoy Staffan de Mistura in Moscow, said he wouldn't rule out a truce that includes Aleppo.
"I hope this decision will be announced at an early date - even within a few hours," Lavrov said, according to Interfax news agency.
The Syrian government had excluded Aleppo from a temporary ceasefire that started Saturday in the capital Damascus, nearby Eastern Ghouta and the coastal area of Latakia.
The mounting death toll in the divided city since an escalation of tit-for-tat shelling and government air raids on April 22 has led to widespread calls for an effective ceasefire.
The opposition Syrian Observatory for Human Rights on Tuesday said that 279 civilians have died since April 22, including 50 killed in a government air raid that hit a hospital in rebel-held eastern Aleppo.
Speaking after his meeting with Lavrov, de Mistura did not specifically mention Aleppo but said he hoped a much-breached cessation of hostilities, which went into effect in late February, could be revived.
The envoy said that "we all hope - and we have to be cautious - but we all hope that this indication, perhaps in the next few hours, will be able to have also a relaunch of the cessation of hostilities under whatever name we want to call it."
State news agency SANA said three people were killed on Tuesday when rebel shelling hit the al-Dhabeet hospital in the city's Muhafaza district.
Rebels had targeted government-held areas across the city since early morning, killing at least 14 people in total, SANA said in a corrected report after initially putting the toll at 20.
The Observatory put the overall death toll at 19.
Once Syria's commercial hub, Aleppo is now divided between the government-held west and the rebel-controlled east, which has been devastated by years of shelling and air raids.
Last week, regime planes hit a hospital in eastern Aleppo killing at least 50 people, among them Wassim Mouaz, the last pediatrician in the city's rebel-held areas.
Lavrov also discussed with de Mistura the floundering Syrian peace talks in Geneva. The opposition suspended its participation in the Geneva talks earlier this month, citing a lack of progress on humanitarian issues and escalating ceasefire breaches.
The Russian minister called the opposition stance "arrogant" and "not constructive," while acknowledging the process of the intra-Syrian talks was "not easy," Russian state news agency TASS reported.
De Mistura said that the next steps would include a meeting of the International Syria Support Group, which brings together outside backers of both the government and the opposition, and possibly a meeting of the UN Security Council "reinforcing all this progress."
German Foreign Minister Frank-Walter Steinmeier has invited Riad Hijab, head of the opposition's Higher Negotiations Committee, de Mistura and French Foreign Minister Jean-Marc Ayrault to discuss a unified return to the table at the next round of peace talks in Geneva.
The German Foreign Ministry said the talks will be held in Berlin on Wednesday.
The Observatory said earlier that airstrikes on Monday night and early Tuesday targeted al-Raqqa, the de facto capital of Islamic State in north-eastern Syria, killing 13 civilians and five militants.
Abdel-Rahman of the Observatory said there were 35 strikes, but did not specify whether they were carried out by Russian planes or the US-led coalition.