The alleged Chinese nuclear explosion on June 22, 2020 was registered by a seismic station in eastern Kazakhstan as two small earthquakes 12 seconds apart near the Lop Nur test site[3][5]. US officials say it was an underground explosion with a magnitude of 2.75, which could be a covert nuclear test[4][5]. According to Assistant Secretary of State Christopher Yeaw, China has conducted this test and is preparing others with capacities in the order of hundreds of tons[3][4]. The international monitoring network IMS can distinguish nuclear explosions only with a power above approximately 500 tons of TNT, therefore the cause of these events cannot be determined with certainty[3]. Satellite images show new tunnels, 30-meter-tall drilling rigs and excavation work at Lop Nur, as well as a laser facility in Sichuan province similar to the US National Ignition Facility[3]. A report by the Center for Strategic and International Studies found no evidence of an explosion because satellite images showed no unusual activity on Lop Nura[4]. China has accused the US of baseless claims being used as a pretext for resuming its own nuclear tests[4]. These events come after the end of the New START treaty, which raises concerns about a new arms race[4].