Aleppo experienced its 'worst' week in the five-year-old Syrian war with six medical facilities being bombed by regime warplanes as Assad's forces advance on opposition strongholds.
A total of six hospitals were bombed by Syrian regime warplanes in Aleppo the week between July 23 and July 31, marking the worst week for attacks on medical facilities the city has seen since the war began in 2011, US-based rights group Physicians for Human Rights (PHR) said on Wednesday.
"Since June, we've seen increasing reports of attacks on civilians in Aleppo and strikes on the region's remaining medical infrastructure," the group's director of programmes Widney Brown said in a statement. "Each of these assaults constitutes a war crime."
In over five years of conflict, PHR has recorded more than 370 attacks on 265 medical facilities in Syria, killing as much as 750 medical personnel.
In April a regime air strike on a hospital killed dozens of people, including the city's last pediatrician.
The Syrian regime, headed by autocrat leader Bashar al Assad, has been making gains across Syria since Russia launched air strikes targeting opposition forces last year.
After capturing the strategic Castello Road last month, which had served as a vital supply route for opposition forces in Aleppo, the regime has been making inroads into the besieged city in preparation for an all-out ground assault.
The regime has designated specific routes to allow the 300,000 civilians remaining in the city to leave and has called on opposition fighters to surrender.
Many aid groups have expressed concern that food and medical supplies in Aleppo could run out within three weeks and have condemned the regime for using starvation as a tool of war.
"The bombings, the lack of humanitarian aid and the failure of the United Nations to deliver any kind of assistance means the death toll may soon be catastrophic," Brown said.
Some estimates put the death toll of Syria's war as high as 470,000 while around half of the country's population has been displaced, triggering the worst refugee crisis since World War II.
A high proportion of the deaths have occurred as a result of regime air strikes, including indiscriminate barrel bombings on civilian areas.
Chemical weapons have also been put to use, with the Assad regime narrowly avoiding a US intervention by surrendering its chemical arsenal after hundreds were killed by a chemical attack on the opposition-held Damascus suburb of Ghouta in 2013.
Despite this, there is evidence that toxic substances like sarin and chlorine are still being used in the war, with both the regime and opposition forces blaming each other.
On Tuesday, the opposition Syrian National Coalition (SNC) accused the Syrian regime of dropping containers of chlorine by a helicopter on a Syrian town close to where a Russian helicopter was shot down in rebel-held Idlib province a day earlier.
Russia says helicopter downed in Syria was delivering "humanitarian aid". Apparent rocket pods in footge of wreckage pic.twitter.com/PqxUYThPvj— John Beck (@JM_Beck) August 1, 2016
The group posted a video on YouTube apparently showing a number of men struggling to breathe and being given oxygen masks by people in civil defence uniforms.
The regime denied responsibility for the attack.
Russia then accused the Nureddin al Zenki opposition group of killing seven people with a "poisonous agent" in the Salaheddin district of Aleppo on Tuesday.