A U.S. think tank said on Thursday that it has observed continuous moves by North Korea to upgrade its main rocket launch site.
 
North Korea-monitoring Web site, 38 North, said recent satellite imagery of the Sohae Satellite Launching Station in North Pyongan Province showed new roads were under construction throughout the site.
 
It also said new guard or observation positions and excavations were also observed near the launch pad with traces of efforts to set up utilities for communications or electricity. 
 
Thirty-eight North said it is difficult to determine the purpose of the upgrades, but their locations suggest that they will be used as observation, telemetry or guard positions.