BAGHDAD, Iraq (CNN) -- Iraqi insurgents in Falluja were storing a huge amount of weapons and explosives in a mosque, U.S. Marines said Thursday.

A statement from the 1st Marine Expeditionary Force called the find the city's "largest weapons cache to date."

The Marines said the Saad Abi Bin Waqas Mosque compound was also being used as a suspected safe house and planning site for insurgents in Falluja, according to the statement.

The statement didn't provide specific numbers of the weapons -- which were discovered by U.S. and Iraqi forces on Wednesday.

The statement did say that the mosque compound was "heavily laden with small arms, artillery shells, heavy machine guns, and anti-tank mines."

"Other buildings within the compound had mortar systems, rocket-propelled grenades, launchers, recoilless rifles and parts of surface-to-air weapons systems. Marines also found the barrel of an anti-aircraft gun outside one of the buildings."

Weapons and explosives also filled the mosque's main prayer building, the mullah's residence and, adjacent to the residence, a small shed that had been "rigged to explode," the statement said.

In addition, Iraqi forces and Marines found a vendor's truck full of explosives, grenades and bomb-making materials. The truck may have been used as a mobile bomb-making factory, the Marines' statement said.

Also, the mosque's rectory contained documents detailing "insurgent interrogations of recent kidnap victims," according to the statement.

Alleged Sunni Muslim rebel supporter Sheik Abdulla al-Janabi also had been using the mosque to preach anti-coalition rhetoric, the statement said...