At least three videos released over the last days show Syrian insurgents firing a previously unseen model of antitank guided missile at regime positions in the provinces of Aleppo and Idlib (here, here and here). Although the caption of one of these videos (followed in this by a previous version of this post) claims that the missiles are French-German-designed Milan, arms expert Brown Moses suggests that these are in fact Chinese HJ-8. Rebels in northern Syria have made growing use of antitank missiles over the last months, but to my knowledge, all models seen previously were Russian-made AT-3, AT-5 and AT7/13 that had been either seized from the regime's stockpiles or shipped from countries such as Libya. The HJ-8 being used by several countries in addition to China, it is difficult to determine the origin of the missiles seen on the videos without further data. The appearance of new weapons in Syria at this stage is unsurprising as numerous reports suggest that Saudi Arabia and Qatar are stepping up their support for the opposition as a response to Hezbollah's growing involvement in the conflict.
The groups using these missiles on the videos are identified as the Nur al-Din Zenki battalions, the Ahfad al-Rasul brigades and the Shuhada' Suriyya batalions and brigades (a notoriously pro-Saudi organisation). All of which recognise the authority of Gen Salim Idriss' Headquarters of the Free Syrian Army, and they recently joined the command centre set up by the FSA in order to supervise the ongoing "Operation Qadisiyya" West of Aleppo.
Added on 25 June, 17:31
I just discovered that video evidences of the use of HJ-8 missiles by the FSA were first reported four days ago on Oryx Blog