Fighting started when government forces fired artillery shells towards Deraa al-Balad in tandem with a ground push.
At least 18 civilians have been killed in Syria’s southern province of Deraa after Russian-backed government forces targeted residential buildings with “surface to surface missiles”, the Syrian Civil Defence said.
The civil defence, also known as the White Helmets – a volunteer search and rescue group operating in rebel-held parts of Syria – said several others were injured in the bombardment on Thursday in the town of Alyadouda.
“The total number of martyrs up until Thursday … is 18,” Mounir Mustafa, a spokesman for the civil defence in Syria’s rebel-held Idlib province, told Al Jazeera.
Mustafa said the civil defence – which no longer operates in Deraa – has been in touch with activists on the ground who have provided the group with the latest death toll.
Thousands of civilians are on the “verge of a humanitarian catastrophe”, the White Helmets said in a statement late on Thursday, adding that “indiscriminate bombing” by Russian-backed government forces has resulted in the killing of “children and innocent civilians”.
The latest round of fighting which began on Monday between government forces and rebels in the area has been described by a United Kingdom-based war monitor as the heaviest clashes since most of the Deraa province came back under government control in 2018.
Fighting started on Monday when government forces fired artillery shells towards Deraa al-Balad – a southern district of Deraa city which is among the areas controlled by former opposition forces – in tandem with a ground offensive, the Syrian Observatory for Human Rights said.
The opposition, residents, and the army said on Thursday the rebels had launched a spate of mortar attacks on Syrian army checkpoints in Deraa.
Several attacks on army outposts near the Damascus-Deraa highway leading to the border crossing of Nassib with Jordan also disrupted passenger and commercial traffic at the main gateway for goods from Lebanon and Syria to the Gulf.
Multiple army checkpoints around key towns and villages from the town of Nawa north of the province to Muzarib near the border with Jordan were also reportedly seized.
The army has sent reinforcements from its elite Fourth Division, run by Syrian President Bashar al-Assad’s brother Maher, senior military defectors said, confirming army leaks.
The opposition forces managed to take control of 18 government military checkpoints in the city, the Observatory said on Thursday.
The attacks on Thursday came after the army launched a dawn operation against the rebel-held old quarter of the city of Deraa, where peaceful protests against decades of autocratic Assad family rule began in 2011 and were met by deadly force before spreading across the country.
The army has sought to reassert its control after the collapse of talks earlier this week to get local elders and former rebels to allow the army to extend its control inside Deraa al-Balad.
The pro-government Al-Watan newspaper called the latest push the “start of a military operation against hideouts of terrorists who thwarted a reconciliation deal”.
Many former rebels stayed in Deraa instead of evacuating under a Moscow-brokered deal three years ago, either joining the army or remaining in control of parts of the province.
The Syrian army, aided by Russian airpower and Iranian fighters, retook control of the strategic province that borders Jordan and the Israeli-occupied Golan Heights to the west in the summer of 2018.
Russian-brokered deals at the time forced rebels to hand over heavy weapons and return state institutions in the enclave but kept the army from entering their neighbourhoods.
However, the army has still not deployed across the whole province. Tit-for-tat bombings and assassinations between former opposition figures and government forces have since become routine.
The province saw a widespread boycott of polls in May that extended al-Assad’s presidency in what officials saw as defiance of state authority.
According to the statement released by the White Helmets, the latest government push is part of “revenge attacks” on those who had refused to participate in the May vote.