North Korea's military lashed out at seven South Korean media outlets on Monday, warning that it had trained missiles on them and demanding South Korean President Lee Myung-bak apologize for perceived insults.

"In case dens of monstrous crimes are blown up one after another, the Lee group will be entirely held responsible for this," the General Staff of the Korean People's Army said in what it called an "open ultimatum" carried by the state-run Korean Central News Agency.

The threat included the unusually specific locations in longitude and latitude of the television networks, radio stations and newspapers.

North Korea objected to coverage that implied that the gathering of 20,000 schoolchildren to celebrate the 66th anniversary of the Korean Children's Union was a propaganda gimmick.

In Seoul, a spokesman for the Unification Ministry, which deals with relations between the two states, indicated South Korea was not taking the threat lightly.

"It's too serious to put aside," ministry spokesman Kim Hyung-suk told reporters.

Especially strained relations

The North's news agency reported on Saturday that the children had pledged loyalty to new leader Kim Jong Un.
"The young delegates could not hold back the endless happiness... amid unchanging longing to remember the benevolent image of respected comrade Kim Jong Un deep in their hearts," it said.

In April, the North had threatened to destroy Seoul and "conservative" media within minutes, prompting South Korea to station police at several media outlets.

Relations between the two countries have been especially strained since the North's failed attempt in April to launch a missile it said was a meant to bring satellite into orbit. South Korea, Japan and the United States said the launch was instead an attempt to test an inter-continental rocket.

ncy/pfd (AP, AFP, dpa)