Beijing, Apr 26 (IANS): Chinese geologists have claimed that North Korea's nuclear test in September 2017 was so strong that it caused an on-site collapse at the Punggye-ri site, the media reported on Thursday.

Using high-quality seismic data to pinpoint the location of several tremors that followed the test, the geologists from the China University of Science and Technology warned that if North were to use the same area for another test, it could cause an "environmental catastrophe".

"North Korea's past tests have altered the tectonic stress in the region to the extent that previously inactive tectonic faults in the region have reached their state of critical failure," CNN quoted the study's lead author, Wen Lianxing, as saying.

"Any further disturbance from a future test could generate earthquakes that may be damaging by their own force or crack the nuclear test sites of the past or the present," he added.

The international community and China have long been concerned that an accident or radiation leak at Punggye-ri could have consequences across the border, reports CNN.

Punggye-ri is located 160 km from China and residents living along the border said they felt the powerful tremor caused by September's test.

Last week, North Korean leader Kim Jong-un said he was ordering the test site to be closed, declaring that Pyongyang no longer needed to test nuclear weapons.