North Korea fires missiles in anger at South, US

Seoul - North Korea fired two missiles into the sea and vowed "merciless" retaliation on Monday as the US and South Korea kicked off joint military drills, denounced by Pyongyang as recklessly confrontational.

The annual exercises always trigger a surge in military tensions and warlike rhetoric on the divided peninsula, and analysts saw the North's missile tests as a prelude to a concerted campaign of sabre rattling.

"And if there is a particularly sharp escalation, we could see the North orchestrating some kind of clash on the maritime border," said Jeung Young-Tae, an analyst at the Korea Institute for National Unification in Seoul.