The leader of the opposition Syrian National Coalition (SNC), Ahmed Moaz al-Khatib, has resigned, according to BBC News.

Khatib wrote on Facebook that world powers had failed to help the rebels, and he could only improve the situation by working outside of the coalition.

Analysts say Khatib believed the SNC was too heavily influenced by Islamists and foreign powers like Qatar. However, a later report claimed that the SNC had refused his resignation and expected him to continue in his post.

The issue that brought matters to a head appears to have been last week's election of a prime minister for an interim opposition government. The SNC chose U.S.-based Islamist Ghassan Hitto to head the alternative administration, which is intended to govern rebel-held areas from inside Syria.

Hitto's election in Istanbul last week was described by some coalition leaders as a "transparent, democratic" election, but it also prompted several resignations from the SNC. And the military wing of the opposition, the Free Syrian Army, has also said it would not recognize Hitto because he had been forced on the opposition.

Khatib said in his statement that he had promised to resign if certain "red lines" were reached, but he did not specify what those red lines were.

"I announce my resignation from the National Coalition, so that I can work with a freedom that cannot possibly be had in an official institution," he said. "For the past two years, we have been slaughtered by an unprecedentedly vicious regime, while the world has looked on. All the destruction of Syria's infrastructure, the detention of tens of thousands of people, the forced flight of hundreds of thousands and other forms of suffering have been insufficient for the international community to take a decision to allow the people to defend themselves."

Khatib, who was elected head of the SNC in November 2012, is seen as a respected and unifying figure in Syria. However, he caused controversy in January by offering talks with Syrian President Bashar al-Assad on condition that 160,000 prisoners were freed.