The UN special envoy for Syria is calling for an urgent meeting of world and regional powers to maintain the deteriorating cease-fire in the country.
Staffan de Mistura said on April 22 that a ministerial meeting of the International Syria Support Group -- which includes the United States, Russia, the European Union, Iran, Turkey and Arab states -- needs to be held.
De Mistura said the political talks on Syria's future are stalled, the cease-fire is unravelling, and much of the limited humanitarian aid deliveries have been blocked.
The cease-fire took effect in Syria at the end of February, but fighting in the country has gradually escalated in recent weeks, particularly around Aleppo.
Reports say air strikes on rebel-held parts of Syria's largest city, Aleppo, have killed at least 25 people and wounded dozens of others.
The Britain-based Syrian Observatory for Human Rights said Syrian warplanes carried out the air strikes, which were in the opposition-held eastern part of the city.
Two barrel bombs reportedly also hit the southern Aleppo district of Bab al-Nayrab, killing an ambulance driver.
Civil defense workers also reported three people killed by artillery in Bustan Al-Qasr, one of the city's most-populated neighborhoods.
At least 270,000 people are estimated to have been killed in Syria's five-year-long conflict, with millions of others forced to flee their homes.
Based on reporting by AFP and Reuters