It's time for the United States to hold Iran accountable.

A dissident group has leaked documents claiming Iranian support to be much larger than previously thought in the Syrian civil war.

Iranian spymasters are commanding a large-scale clandestine war from Damascus in order to support Syrian President Bashar Assad, The Daily Mail reported Thursday.

The National Council of Resistance (NCRI) of Iran has claimed that Iranian Supreme Leader Ayatollah Ali Khamenei has spent billions to bolster its ally Assad in the last five years, including running operations from a five-floor building dubbed the "Glasshouse" near the airport in the country's capital. 

The NCRI claims that the Iranian headquarters play a vital role alongside Russia in supporting Assad's regime. The Iranian HQ holds intelligence, counter intelligence operations and has millions of dollars that are flown from Tehran, according to NCRI claims.

The documents could not be verified independently but were describes as "credible" by "intelligence experts," making the claim that Iran is in control of the largest fighting force in Syria. The documents also point to military bases spread throughout the war-plagued state, with cash reserves far greater than previously thought to support the Syrian regime.

If the claims are correct, the fundamentalist regime and its proxies, mainly Shi'ite paramilitary groups, are much more powerful than previously estimated, with western analysts approximating a fighting force of 16,000.

Visit the Jerusalem Post to read more about Iran's participation in the war in Syria.