Experts who examined the images said they believe construction is related to Israel's suspected nuclear weapons program, which could draw international criticism after Israel and the United States bombed nuclear sites across Iran in June

Construction work has intensified on a major new structure at a facility key to Israel's long-suspected atomic weapons program, according to satellite images analyzed by experts. They say it could be a new reactor or a facility to assemble nuclear arms – but secrecy shrouding the program makes it difficult to know for sure.

The work at the Shimon Peres Negev Nuclear Research Center near the city of Dimona will renew questions about Israel's widely believed status as the Middle East's only nuclear-armed state.

It could also draw international criticism, especially since it comes after Israel and the United States bombed nuclear sites across Iran in June over their fears that the Islamic Republic could use its enrichment facilities to pursue an atomic weapon. Among the sites attacked was Iran's heavy water reactor at Arak.

Seven experts who examined the images all said they believed the construction was related to Israel's long-suspected nuclear weapons program, given its proximity to the reactor at Dimona, where no civilian power plant exists. However, they split on what the new construction could be.