Damascus, Aug 20 (IANS): A total of 6,300 rebel fighters joined the Islamic State (IS) militant group last month alone, the Syrian Observatory for Human Rights reported has said.

The Observatory Tuesday said 6,300 fighters had joined the training camps of that Al Qaeda breakaway group in Syria's northern provinces of al-Raqqa and Aleppo, Xinhua reported.

Among them, 5,000 recruits are Syrians, the Observatory said, adding that the rest are newly-recruited fighters.

The Observatory, which relies on a network of activists on the ground, said that 1,300 fighters are Arab and foreign nationals, adding that a majority of them entered Syria from Turkey.

It said that the IS pays a single Syrian fighter 400 dollars a month. In case of married militants, their kids and spouses also get paid. As for fighters from overseas, they have a monthly pay of 800 hundred dollars.

The IS, previously known as the Islamic State in Iraq and the Levant (ISIL), has recently proclaimed it established an " Islamic Caliphate" in parts of Syria and Iraq, threatening the political geography of the region.