(CNN) Four Russia-based nuclear monitoring stations that monitor radioactive particles in the atmosphere have mysteriously gone quiet after an August 8 explosion at a Russian missile testing facility, an explosion that has sparked confusion and concerns about possible increases in radiation levels, according to the Comprehensive Nuclear-Test-Ban Treaty Organization.

CTBTO is an independent body which watches for nuclear weapons testing violations with over 300 monitoring stations around the world. Both Russia and the US are signatories to the treaty.

The two Russian radionuclide stations, called Dubna and Kirov, stopped transmitting data within two days of the explosion, the organization said.

"According to our routine global procedure, the CTBTO contacted the Station Operators as soon as the problems started. They have reported communication and network issues, and we're awaiting further reports on when the stations and/or the communication system will be restored to full functionality," a spokesperson said.

In addition, a senior CTBTO official tells CNN that stations in Bilibino and Zalesovo went silent on August 13.

Read More