Radio Free Asia(RFA) reported on Thursday that a large apartment complex is being built near North Korea's main nuclear facility, indicating that more people live around there and possibly work at the plants.

Curtis Melvin, a researcher at the US-Korea Institute at Johns Hopkins University, told RFA that a total of 15 apartment buildings have been built since 2014 in areas west of the Yongbyon nuclear complex in North Pyongan Province.

Providing satellite images of the apartment complex, Melvin said it indicates that a growing number of people is working at the nuclear facilities in Yongbyon and the adjacent nuclear-related research centers.

Melvin said the continuous construction of apartment units in the area is a clear suggestion that the North Korean regime is continuing developing its nuclear program, introducing a recent announcement by a U.S. think tank that the Yongbyon nuclear facility has been continuously operated.

He also explained recent changes around the nuclear site, including the existence of apartment construction sites and markets.