Nusra Front fighters rest with their weapons behind sandbags in the Sheikh Maksoud neighborhood of Aleppo, Syria August 3, 2015. Reuters

Reuters/ Beirut

Syria's al Qaeda affiliate Nusra Front abducted five more rebels believed to have been trained by the United States after raiding  areas along the Turkish border in the past 24 hours, a war monitoring group said on Tuesday.
The British-based Syrian Observatory for Human Rights said the militant group was now holding a total of 13 men from "Division 30", a Syrian rebel unit that includes some fighters recently trained by the US military.
It was not immediately clear whether the five men abducted overnight had been on the new US military training programme or on an existing, separate CIA-led programme.
On Friday, Nusra Front said in a statement it had detained a number of Syrian rebels trained by the United States and warned any others they should abandon the programme.
But the Pentagon said at the time that no members of an initial group of around 60 US-trained rebels had been abducted.
The US military launched a programme in May to train up to 5,400 fighters a year in what was seen as a test of Obama's strategy of getting local partners to combat the hardline Islamic State group in Syria.
The training programme has been challenged from the start, with many candidates being declared ineligible and some even dropping out.
On Monday, US officials said one member of this new Syrian force was believed to have been killed in clashes last week with Nusra Front.
The al Qaeda wing attacked a rebel compound near Azaz town in Syria on Friday, triggering the first US air strikes to support members of the new Syrian force.
The Observatory, which tracks violence across the country, said at least five members of Division 30 were killed in the clashes that also left at least 25 Nusra Front fighters dead and wounded scores.