Forecasting site Stratfor.com says the images published Monday show Iran building a tunnel into a heavily guarded mountain complex inside the Parchin facility, some 20 miles southeast of Tehran, while also working to erase signs of alleged high-explosive testing at another area on the site.

“We’re not saying they’re cheating on the nuclear deal,” Stratfor analyst Sim Tack told The Daily Beast. “The images show Iran was going through the motions to hide what it’s done before, and it is still…developing facilities that the IAEA may or may not have access to,” Tack said, referring to the International Atomic Energy Agency.

The progression of satellite images tracking construction at Parchin from 2012 to 2015 show how Iran’s leaders apparently worked to keep regime hardliners happy by moving forward with weapons programs, even as the leadership worked to erase signs of an illegal nuclear weapons program, Tack said.

The satellite images appear to show new paving around the building that was alleged to be a test site for high-energy explosive charges used to detonate a nuclear weapon.