SEOUL, South Korea — Tensions on the Korean peninsula flared again Monday as South Korea fired warning shots at a North Korean patrol boat, one day after Pyongyang provoked international condemnation with a controversial satellite launch.
The South fired the shots and broadcast loudspeaker messages at the Northern vessel after it crossed a maritime boundary known as the Northern Limit Line, an official from the South's defense ministry said on condition of anonymity.
The Northern vessel crossed the line in the Yellow Sea at around 6:55 a.m. (4:55 p.m. ET Sunday) and retreated about 20 minutes later following the shots and messages, the official added, saying that the South was "fully prepared for North Korean provocation."
The five warning shots were fired into the sea by a naval gun, according to Reuters.
Pyongyang does not recognize the maritime boundary, drawn up after the 1950-53 Korean War, and its boats have crossed it on several occasions.
However, tensions are running particularly high in the area after Pyongyang on Sunday launched what it said was an observation satellite.
The U.S. and its allies, as well as the United Nations, condemned the launch as a smokescreen to test ballistic-missile technology — defying U.N. sanctions.
Secretary of State John Kerry slammed decried the "flagrant violation," and U.S. Ambassador to the U.N. Samantha Power called for sanctions "to affect the calculus of a regime that has brazenly and recklessly acted in defiance of international norms."
The U.N. Security Council held an emergency meeting Sunday in response to the launch, saying after that it would "expeditiously" adopt a new resolution in response to what it called "dangerous and serious violations."
Sunday's launch came on the heels of another perceived provocation from Pyongyang. Last month it conducted its fourth nuclear test. It said the device was a hydrogen bomb but this claim was doubted by outside observers.
This article first appeared on NBCNews.com.