The United Nations peace envoy for Syria, Staffan de Mistura, ended a three-day trip to Damascus Wednesday, condemning the deaths of civilians in both government and rebel fire, according to AFP.
De Mistura met government officials, including President Bashar Al-Assad, during the visit, briefing them on consultations he is holding in Geneva with various parties to the conflict.
His spokeswoman said de Mistura's meetings also focused on "the necessity of protecting civilians."
"He underlined once again that the use of barrel bombs is unacceptable," a statement quoted by AFP said.
Barrel bombs are crude weapons — containers packed with explosives and scrap metal that are typically dropped from helicopters.
Their use has been criticized by human rights groups because of the indiscriminate death toll they cause among civilians when dropped on residential areas.
Assad, however, has repeatedly denied using barrel bombs and has suggested in interviews that no such weaponry exists
De Mistura also specifically condemned government shelling and aerial bombardment on Tuesday of the rebel-held area of Douma, which killed at least 24 people, according to a Britain-based monitor.
And he condemned rebel forces for attacks targeting civilians in both Damascus and Aleppo.
At least 34 people, including 12 children, were killed Monday in rebel fire on the government-controlled western portion of Aleppo city.
And nine people were killed Tuesday evening in opposition fire on a garden in central Damascus.
The statement said de Mistura "underscored the dire humanitarian situation on the ground and he insisted on greater access to besieged areas and conflict-affected communities, particularly in light of the (Muslim fasting) month of Ramadan" that begins Thursday.
In addition to government officials, de Mistura met more than 30 political, religious and civil society figures, according to AFP.
De Mistura launched a fresh round of consultative talks in Geneva with regional and local stakeholders in Syria's conflict, including Iran, on May 5. Last week he announced that he had extended the wide-ranging talks by another month until July.
Participants have included government officials and members of the opposition-in-exile National Coalition, as well as representatives from regional countries, policy experts and civil society groups.
De Mistura is the third UN envoy to tackle Syria's conflict, and had previously angered rebel groups by saying President Bashar Al-Assad was as "part of the solution" to the conflict in Syria.