North Korea has threatened to attack South Korea "without notice" in response to anti-Pyongyang rallies on the anniversary of the death of its former leader.
The threat to launch an unannounced strike by the nuclear armed state was conveyed in a fax sent from the North's National Defence Commission to South Korea's National Security Council, according to Yonhap news agency.
Some protesters reportedly burnt photographs of the current leader, Kim Jong-un, an action condemned in North Korea as an insult of the "highest indignity".
The South Korean government reportedly responded immediately to Pyongyang's threats of attack, with a vow to "sternly react" to any provocations. Tensions have, once again, flared in the region after the young leader last week publicly executed his uncle Jang Song-thaek in a bid to consolidate his grip on power.
North Korea has a long history of issuing bellicose threats to South Korea, with military officials reporting on this occasion that there currently were no signs of unusual activity.
Seoul, a city of 10 million people, is known to be within range of the conventional artillery operated by North Korean soldiers along the heavily fortified border.
The threats came as Dennis Rodman, the former US basketball star, controversially arrived in North Korea on his third trip since he first visited the renegade state in February.
The sportsman, accompanied by a documentary crew, is scheduled to spend four days training a national team of North Korean basketball players for a exhibition in Pyongyang.
Despite requests from defectors and organisations to highlight the human rights abuses in the hardline regime during his visit, he has refused to be drawn on political issues, insisting his visit is for "fun" not politics.
Rodman held trials for a North Korean team to face a dozen NBA veterans in an exhibition game on Kim Jong-un's birthday next month.
The star said plans for the January 8 game are moving ahead but some of the 12 Americans he wants are afraid to come. "You know, they're still afraid to come here, but I'm just telling them, you know, don't be afraid man, it's all love, it's all love here," he said.
Rodman, who arrived in Pyongyang on Thursday, said he expects to announce the roster soon. He also said he is planning another game in June. (© Daily Telegraph, London)