BEIRUT – Issuing Tehran's strongest warning to date, a top Iranian official said Saturday that any attack on Syria would be deemed an attack on Iran, a sign that it will do all it can to protect embattled Syrian President Bashar Assad.

Ali Akbar Velayati, an aide to Iran's supreme leader Ayatollah Ali Khamenei, made his comments as Syrian troops conducted offensive air raids against rebels and discovered a trio of tunnels they were using to smuggle weapons in their fight to topple Assad.

The world has been grappling over how to deal with Syria ever since an uprising against Assad's regime erupted nearly two years ago. But so far, there has been no international intervention on the ground where more than 60,000 people have been killed, according to the U.N.