SEOUL • North Korea fired a ballistic missile from a submarine yesterday but it appeared to have failed soon after launch, South Korea's military said.

The launch came at the end of a week of sharply rising tensions on the peninsula. It was only a day after the United States and South Korea pledged to deploy an advanced anti-missile system to counter threats from Pyongyang, and two days after North Korea warned it was planning its toughest response to what it deemed a"declaration of war" by the US.

That followed Washington's blacklisting of the isolated state's leader Kim Jong Un for alleged human rights abuses.

The South's Office of the Joint Chiefs of Staff said in a statement that the missile was launched at about 11.30am Seoul time in waters east of the Korean peninsula.

The missile was likely fired from a submarine as planned but appeared to have failed in the early stage of flight, the joint chiefs said.

Neighbouring Japan, the US and South Korea's military condemned the missile launch as a flagrant violation of UN sanctions.

South Korea's Yonhap news agency said the missile engine successfully ignited but the projectile soon exploded in mid-air at a height of about 10km, and covered not more than a few kilometres across the water.

The South's military declined to confirm the details, citing its policy of not publicly commenting on intelligence. It said the missile was detected in the sea south-east of the North Korean city of Sinpo.

According to experts, satellite images indicate that Pyongyang is actively trying to develop its submarine-launched ballistic missile programme in this area.

The missile launch is a "clear challenge to UN Security Council resolutions", Japanese Prime Minister Shinzo Abe said yesterday, according to Kyodo news agency. "We should strongly condemn the launch by working with the international community," he said.

REUTERS