North Korea fires about 10 ballistic missiles toward sea as border tensions rise

North Korea fired about 10 short-range ballistic missiles toward the sea on Thursday, South Korea's military said, days after the North threatened to restart front-line propaganda loudspeaker broadcasts and deploy new weapons along the rivals' tense border.

The Joint Chiefs of Staff said the missiles were detected from the eastern coastal town of Wonsan. South Korea said it bolstered its surveillance posture and was closely exchanging information with the United States and Japan.

The launches came hours after North Korean leader Kim Jong Un returned from a surprise weekend visit to China, his main ally and economic lifeline. The trip was his sixth to China since taking office in late 2011; he travelled to the border city of Dandong over a newly inaugurated bridge to pay respects at a memorial to China's role in the 1950-53 Korean War, and later met senior Communist Party official Wang Huning.

Animosity between the Koreas has deepened since landmine blasts on September 21 wounded three South Korean soldiers. Seoul accused the North of planting mines south of the military demarcation line; Pyongyang denied responsibility and warned of retaliation. North Korea then said it would restart propaganda broadcasts and deploy new weapons systems along the border, calling out what it described as repeated warning shots by South Korean troops. South Korea proposed talks to clarify the border and prevent accidental clashes, but has received no response.

Thursday's barrage was the latest in a series of weapons tests in recent weeks, including submarine-launched cruise missiles and hypersonic missiles. Analysts say Kim is likely trying to pressure Washington into concessions as US President Donald Trump says he wants to restore diplomacy. Kim has also been rebuilding ties with Beijing after years of prioritising Russia, to which the North has sent troops and ammunition for the war in Ukraine. (With inputs from PTI and media reports)