A Syrian activist and member of anti-Isis group, "Raqqa is Being Slaughtered Silently", and his friend were found beheaded in a house in Urfa, Turkey, on Friday. 

"Raqqa is Being Slaughtered Silently" is a group of Syrian activists who have been highlighting atrocities in the country committed by Islamic State terrorists as well as by forces belonging to Syrian President Bashar al-Assad. 

Isis has claimed responsibility for the beheadings, the group claimed. The killings took place in Turkey's Urfa city. 

The group shared images of its member Ibrahim Qader and the second man identified as Fares on it Twitter account. 

"One of our member called "Ibrahim" and another friend called "Fares" was found slaughtered in their house in Urfa," the group said. 

Isis has increasingly made its presence felt in Turkey and is believed to be behind the deadly Ankara train station bombings that killed nearly 100 people earlier this month. 

Turkey goes to polls on Sunday.