North Korea’s sixth nuclear test may be on the way according to the new satellite imagery of the nuclear test sites.  
New satellite imagery shows that N. Korea has laid communication wires and continued presence of three to four vehicles or equipment trailers at its nuclear test site. They are used to initiate test, collect data from the explosion and process the data. 

Moreover, water has been pumped out of the portal and drained downhill to the east and west. This is estimated to keep the tunnel dry for monitoring or communications equipment. 

Further, up to 100 people have been seen to gather around the main administrative area. Such gathering has not been seen since 4 January and 12 February 2013, the last two nuclear tests. 

“The combination of these factors strongly suggests that test preparations are well underway, including the installation of instrumentation,” 38 North said. 

“There is no significant activity at the other areas of the test site. The lack of activity may mean that test preparations are in their final stages.” 

However, it is yet to declare it a nuclear test because N. Korea could be using deception methods. 

“The North Koreans know when commercial satellites are passing overhead and typically try to avoid activities during time. The fact these formations can be seen suggests that Pyongyang is sending a political message that the sixth nuclear test will be conducted soon,” they added. “Alternatively, it may be engaged in a well-planned game of brinkmanship.”