ISIS kidnapped dozens of Druze women and children when it attacked their village last week in Syria's Sweida, it has been revealed.

Sweida, which is mainly government-held and populated with members of Syria's Druze minority, had been largely insulated from the conflict raging in the rest of the country since 2011.

But on Wednesday, a string of suicide blasts and shootings claimed by ISIS left more than 250 people dead in the provincial capital and nearby villages, most of them civilians.

During the attack, ISIS jihadists also abducted several dozen women and children from one village, according to the Syrian Observatory for Human Rights and Sweida residents.

Coffins are lined up during a mass funeral on July 26 following deadly suicide attacks in the southern city of Sweida in Syria

The Britain-based Observatory said 36 Druze women and children were abducted, but that four women had since managed to escape while another two had died.

That left 14 women and 16 children in ISIS captivity, said Observatory head Rami Abdel Rahman. Another 17 men were unaccounted for but it was unclear if they were also kidnapped.

ISIS has not claimed the kidnappings and no details on them could be found on its propaganda channels.

According to news outlet Sweida24, the 36 civilians were kidnapped Wednesday from the village of Al-Shabki, in the eastern hinterlands of Sweida province.

Sweida24 and other online outlets published a video that appeared to show one of the female hostages making demands of the Syrian government on behalf of ISIS.

AFP could not independently verify its authenticity, but several Sweida residents confirmed the woman was among those missing after the attacks.

Fruits are seen scattered on the ground after a suicide bombing in Sweida, in southern Syria, on July 25

Druze, who made up three percent of Syria's pre-war population, are monotheistic and considered Muslim, but the sect is otherwise highly secretive, includes mystical elements like reincarnation, and does not allow new converts.

They are regarded as heretics by Sunni Muslim extremist groups including ISIS.

The hostages mainly hail from two large families in Al-Shabki, said reporter Nour Radwan, who heads Sweida24.

The remote village suffered some of the deadliest violence from Wednesday's attacks, with more than 60 civilians killed there, Radwan said.

'Most of its residents are farmers and don't have much more than hunting rifles in terms of weapons, so there was little resistance from Al-Shabki compared to other villages,' he told AFP.

'When ISIS saw that, it kidnapped a first batch of people from their homes and took them east towards the Badiya, according to survivors,' Nour added.

The Badiya is Syria's vast desert stretching from the country's centre to its eastern border with Iraq, and it includes several isolated ISIS-held pockets.

ISIS then reached out to the hostage's families with pictures, videos, and ransom demands.

The jihadists want the Syrian government to release 'detained ISIS-linked people, whose numbers are now being negotiated,' and stop its offensive on nearby ISIS positions, said Radwan.

Druze religious leaders have since stepped in, Radwan and another source with knowledge of the talks told AFP.

People attend the funeral processions for victims of the suicide bombings that hit al-Sweida province onJuly 25

'As of Sunday, the hostages were still being held in the Badiya. Negotiations are happening between Daesh (ISIS) and Druze sheikhs,' said the source.

'The massacres were massive, and so is the pain. There are families that were entirely wiped out,' said Noura al-Basha, an activist from Sweida.

'One young man from the Abu Ammar family in Al-Shabki lost his father and brother in the attacks. His mother was unaccounted for until they found her two days ago near the village, and his cousins are among those kidnapped,' Basha told AFP.

In addition to territory it holds in the Badiya, ISIS also controls a pocket in Daraa province, directly west of Sweida.

Backed by Russia, Syrian troops have been waging an assault on that ISIS-held patch for nearly two weeks.

On Monday, they overran the jihadist-controlled town of Ash-Shajara just a few hours after beginning to bomb it, Syrian state media said.

That has left just three villages under ISIS contol in Daraa, said the Observatory, but there are fears that hundreds of jihadists may have slipped away unharmed.

Since its bloody rise in 2014, IS has carried out multiple mass abductions in Syria and Iraq, including of minorities.

It kidnapped more than 220 Assyrian Christians in northeast Syria in 2015 and another 270 Christians from a central village the following year. Most of the hostages were released after negotiations.

Under the group's ultra-conservative interpretation of Islam, minorities are considered 'infidels' but IS also politicises them as regime loyalists.

More than 350,000 people have been killed since Syria's conflict erupted in 2011.

Wednesday's violence was the worst Sweida had seen since the war began, and one of the deadliest attacks by IS across the country.

ISIS attackers detonated suicide bombs in Sweida city and villages to the north and east, while others shot and stabbed residents.

A total of 139 civilians were among more than 250 people killed, according to the Observatory. The other dead were pro-government fighters or residents who picked up arms to defend their homes.