North Korea: Tremor detected near weapon test site

A magnitude 3.4 earthquake has been detected in North Korea.

The earthquake occurred about 50km (31 miles) from a nuclear test site, monitors say. Previous quakes were caused by weapon tests.
Chinese seismologists said it was a "suspected explosion" but South Korea says that it could be a natural quake not caused by a nuclear test.
The US Geological Survey (USGS), meanwhile, said it could not yet make a judgment as to the cause.
North Korea carried out a massive nuclear test on 3 September which was widely condemned at the UN.
The size of Saturday's tremor is smaller than the earthquakes registered as a result of all of North Korea's six nuclear tests.
After the last test, which North Korea said was a hydrogen bomb, initial reports from the USGS put the tremor at magnitude 5.6 with a depth of 10km but this was later upgraded to magnitude 6.3 at 0km.

http://www.bbc.com/news/world-asia-41371867