Russia's significant and ongoing support for Syrian dictator Bashar al-Assad was exposed by rebels who recently overtook a signals intelligence base jointly run by Syria and Russia, a report this week claims.

Free Syrian Army fighters discovered that the base was used to spy not only on anti-Assad rebels, but also on Israel, Jordan and Saudi Arabia. A recent upgrade in the base's equipment was driven by Iran, which was worried spying on Israel was being forsaken to focus on Syria's civil war, the report on a website called the Oryx Blog said.

A map showing Israeli military positions in the northern part of the country was found on a wall inside the spy center.

The base is in a town called Tel Al-Hara, which is close to a border crossing with Israel. It was run by the Russians, a follow-up report in Haaretz said.

Israeli and U.S. officials have been mum about the findings inside the Syrian base, or about Russia's significant contribution to the spy operation on behalf of Assad, Hizballah and Iran.