The group and opposition activists also revealed that the attackers also stole two vans, helmets and walkie-talkies.
"7 SCD volunteers were killed by unknown armed men in Sarmin SCD center, Idlib, in the morning", the White Helmets said.
Ankara, Beirut- Rage prevailed in Idlib on Saturday after seven volunteers with the Syrian civil defense rescue service were killed in a shooting by unidentified attackers in rebel-held Idlib province on Saturday, while Turkey continued to adopt restrictions to control the border with Syria.
"Colleagues came in the morning for the change of shift and found them dead", its director, Rami Abdel Rahman, said.
Sarmin is controlled by the Hayat Tahrir al Sham jihadist alliance, which was formed when the Nusra Front merged with other groups.
The organization was nominated for the Noble Peace Prize in 2016 but didn't win - it commenced operations in 2013 and the volunteers have been known since 2014 as the White Helmets for the sake of the helmets they put on their heads.
Although they work exclusively in rebel-held areas, they are non-partisan.
They receive funding from a number of Western governments, including Britain, Germany, the Netherlands and the United States.
President Bashar al Assad's government, meanwhile, accuses the group of faking videos and being a tool of its global donors.
Critics also accuse them of harbouring rebel fighters, including Islamist militants, in their ranks.
No group has yet claimed responsibility for the attack. The footage was widely circulated on social media and was shown on news channels all over the world.
Last year, it was the subject of an Oscar-winning documentary which showed the group's heroic efforts in desperate and risky situations.