The UN special envoy to Syria has called for a truce again around the city of Aleppo as activists report more deaths in fighting around the country.

Activists said 33 people were killed in fighting in Aleppo on Saturday when air strikes targeted the city's southern edges and intense battles raged, the AFP news agency reported.

More than 300 civilians have been killed in a three-week surge of fighting in the city and bombardment, according to a monitoring group.

Staffan de Mistura, the UN envoy, has long called for a 48-hour halt in fighting each week to allow aid delivery and medical evacuations from both opposition-held eastern and regime-controlled western Aleppo.

"You may wonder what's the good of a truce in such a terrible war. Well, I can assure you and I've seen it in the past that a truce can save lots of lives and is a breath of fresh air for people being besieged," De Mistura said on Saturday.

"A truce can give the possibility for people to stop and think that it is probably best to negotiate because no one is winning and those who are losing their lives are the Syrians."

Among those who died in Aleppo on Saturday was the older brother of Omran Daqneesh, the little Syrian boy who was pictured sitting in an ambulance dazed and covered in blood after an air strike.

Ali Daqneesh died from wounds sustained in the August 17 attack on the family's apartment in Aleppo, according to the SOHR.

"Ali, aged 10, succumbed to his injuries. He was badly wounded in the same bombardment as Omran ..."

PHOTO CAPTION

A general view shows rising smoke from burning tires, which activists said are used to create smoke cover from warplanes, in Aleppo, Syria August 1, 2016 (Reuters).

Al-Jazeera