Turkey added al-Qaeda's franchise in neighboring Syria to a list of terrorist organizations on Tuesday, in a sign of the country's growing concern over the rise of radicals across the border.

Although other jihadist groups fighting in Syria's civil war claim to be inspired by al-Qaeda, the al-Nusra Front is the only one to be officially sanctioned by the group's leader, Ayman al-Zawahiri.

Rights groups have accused the al-Nusra Front of committing war crimes against civilians in Syria, including executions and hostage taking.

Turkey, which backs the uprising against President Bashar al-Assad, has repeatedly denied claims that it is providing shelter or backing al-Qaeda linked groups in Syria.

The decision to add Al-Nusra Front on the "list of Al-Qaeda linked organisations" was published in Turkey's Official Gazette .

Ankara has long championed robust support for Syria's fragmented opposition but the growing influence of al-Qaeda affiliated groups in the war-torn country left it open to accusations that it is backing radical Islamists.

Last year, Turkish Foreign Minister Ahmet Davutoglu dismissed concerns over al-Nusra, insisting that Ankara was supporting only the opposition Syrian National Coalition and the Supreme Military Council -- neither of which include al-Nusra members.

Nusra is thought to be made up of predominantly Syrian citizens, and enjoys some level of support among more moderate rebel groups.

Despite sharing an ideology, al-Nusra Front is considered to be a less radical force than Syria's other main al-Qaeda-inspired group, the Islamic State of Iraq and Syria (ISIS).

Al-Qaeda has carried out attacks on Turkish soil before. In 2003, four suicide car-bomb attacks on two Istanbul synagogues, the British consulate and British bank HSBC killed 63 people, including Britain's consul general. They were claimed by an al-Qaeda cell.

(AFP)