Satellite imagery revealing potential nuclear cover-up activity in Iran. Photo: ISIS.

The U.S. has intensified its covert intelligence gathering operations at Iran’s Bushehr nuclear plant over the past two months due to concerns over safety hazards at the plant, the Wall Street Journal reported Monday.

The report said statements made by U.S. officials revealed that there were problems at the plant with the storage of enriched plutonium, due to the sudden disassembly of fuel rods at the plant by Iranian technicians last October.

U.S. nuclear experts reportedly said they were worried about safety and security at the plant because they believe that Iran’s leaders were using the facility to advance their nuclear weapons program.

According to the report, spying on the plant is routinely carried out by the U.S. using unmanned aerial vehicles operating in the Persian Gulf area, among other methods. Senior U.S. officials said advanced eavesdropping systems on the UAVs intercepted transmissions of photos and other communications from inside the Bushehr facility.

The sudden disassembly of fuel rods at Bushehr two months ago was said to be viewed as a warning signal in the U.S. administration, which has recently been focusing more on activities at the Natanz and Qom nuclear facilities.