North Korea nuclear test - latest updates

Summary

North Korea claims "perfect success" in hydrogen bomb test
State TV says device can be loaded onto a missile
South Korean leader Moon calls for "strongest response"
Japan confirms North Korea carried out its sixth nuclear test
North Korea's biggest test yet caused a 6.3 magnitude earthquake

Live Reporting

Alastair Lawson and Vicky Baker

Japan's Abe says nuclear test 'absolutely unacceptable'published at 06:01 British Summer Time 3 September 2017
Japan's Prime Minister, Shinzo Abe, has reacted to suggestions that a 6.3 magnitude earthquake detected in North Korea is a nuclear test.
Mr Abe said if Pyongyang had carried out such a test, it would be "absolutely unacceptable".
South Korean national security council to meetpublished at 05:59 British Summer Time 3 September 2017
South Korean officials have called a national security council meeting after tremors near a North Korean nuclear site, Yonhap news agency reports.
A quake, which has been upgraded to a 6.3 magnitude by the US Geological Survey, raises speculation this could be North Korea's sixth nuclear test.
Quake location 'near North Korean nuclear site'published at 05:50 British Summer Time 3 September 2017
Image source, CNES
South Korea officials said the quake took place in Kilju County, where the North's Punggye-ri nuclear test site is situated.
The South's military chiefs said the North was "presumed" to have conducted a nuclear test.
Initial reports from the US Geological Survey put the tremor at 5.6 magnitude with a depth of 10km (six miles) but this was later upgraded to 6.3 magnitude at 0km.
North Korea carried out its last nuclear test in September 2016. It has defied UN sanctions and international pressure to develop nuclear weapons and to test missiles which could potentially reach the mainland US.
North Korea 'has missile-ready nuclear weapon'published at 05:46 British Summer Time 3 September 2017
Image source, EPA
Earlier the BBC reported North Korean leader Kim Jong-un had inspected a new hydrogen bomb, which Pyongyang claimed could be loaded on a ballistic missile.
There has been no independent verification of the claims.
Pyongyang has defied UN sanctions and international pressure to develop nuclear weapons and to test missiles which could potentially reach the United States.
State news agency KCNA said Kim Jong-un had visited scientists at the nuclear weapons institute and "guided the work for nuclear weaponisation".
China claims second earthquake minutes after firstpublished at 05:41 British Summer Time 3 September 2017
Breaking
The China Earthquake Networks Centre (CENC) has reported that a second tremor has occurred in a similar location in North Korea, about eight minutes after the first.
The second quake was recorded by the agency at 11:38 in Beijing, which is 04:38 BST.
The agency reports it was a 4.6 magnitude earthquake, and described it as a "collapse".
The first earthquake was caused by what CENC called a "suspected explosion".
USGS claims North Korea earthquake 6.3 magnitudepublished at 05:36 British Summer Time 3 September 2017
Image source, USGS
The United States Geological Survey, external has upgraded the magnitude of the earthquake, 22km away from Sungjibaegam, saying it was 6.3 magnitude.
The USGS adds that if the event was caused by an explosion, it would not be able to ascertain whether it was the result of a nuclear explosion.
'Earthquake detected near North Korea nuclear site'published at 05:32 British Summer Time 3 September 2017
Breaking
The South Korean military says it has registered an earthquake of 5.6 magnitude near a nuclear test site in North Korea.
It comes hours after Pyongyang claimed it had developed a hydrogen bomb capable of being loaded on to a ballistic missile.
The South Korean military added it appeared the earthquake was man made.