Talks continue between North and South Korea
Senior officials from North and South Korea have resumed a second round of talks that temporarily pushed aside vows of imminent war on the peninsula.
The talks restarted in the border village of Panmunjom, South Korea's presidential office said.
The delegates failed to reach an agreement in Saturday's marathon talks that stretched into the early hours of Sunday, and it was still unclear whether diplomacy would defuse what has become the most serious confrontation in years.
South Korea's military reported on Sunday that it detected unusual troop and submarine movements in North Korea that indicated Pyongyang was strengthening its capacity for a possible strike.
About 70% of the North's 77 submarines had left their bases and were undetectable by the South Korean military as of Saturday, said an official from Seoul's defence ministry.
The official also said that the North had doubled the strength of its frontline artillery forces since the start of the high-level talks early on Saturday evening.
The talks involve Kim Kwan-jin, presidential national security director, and unification minister Hong Yong-pyo, from the South Korean side, and from the North, Hwang Pyong So, the top political officer for the Korean People's Army, and Kim Yang Gon, a senior official responsible for South Korean affairs.
Mr Hwang is considered by outside analysts to be North Korea's second most important official after supreme leader Kim Jong Un.
The first round of the talks started shortly after a deadline set by North Korea for the South to dismantle loudspeakers broadcasting anti-North Korean propaganda at their border. North Korea had declared that its frontline troops were in full war readiness and prepared to go to battle if Seoul did not back down.