A 5.3 magnitude earthquake in North Korea, that is being labelled as an 'artificial earthquake' by Seoul, has triggered sharp reactions from US, Japan and China, apart from South Korea.
The White House, that did not confirm reports of a nuclear test, has said it is assessing the explosion.
"We are aware of seismic activity on the Korean Peninsula in the vicinity of a known North Korean nuclear test site," National Security Council spokesman Ned Price has been quoted as saying by AFP.
Speculations are rife that the seismic event, detected near North Korea's Punggye-ri nuclear test site, was recorded as a result of a 'fifth nuclear test' by the country following the January test.
Japanese Prime Minister Shinzo Abe reacted strongly saying that nuclear test by North Korea could not be tolerated and that Japan would protest strongly to Pyongyang if confirmed.
Meanwhile, Lassina Zerbo, the head of world monitoring agency Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) told Reuters that the seismic activity produced by a suspected North Korean nuclear test is larger than an earthquake triggered by a nuclear test in the same area in January,
"It's a larger signal than last time," Zerbo said, referring to the earthquake triggered by North Korea's January 2016 nuclear test.
Lassina Zerbo, executive secretary of the Comprehensive Nuclear Test Ban Treaty Organisation, said the agency was processing unusual seismic activity in the Korean peninsula from its 25 stations monitoring the region.
Meanwhile, China's environment ministry has begun emergency radiation monitoring along border regions in northeastern China after North Korea carried out a suspected nuclear test, state television said on its official microblog on Friday.
(WION with inputs from Reuters)