http://www.bbc.co.uk/news/world-asia-16239693 check link for a video .
The BBC's Lucy Williamson says news of the death has taken people by surprise
North Korean leader Kim Jong-il has died of a heart attack at the age of 69, state media have announced.
Millions of North Koreans were "engulfed in indescribable sadness", the KCNA state news agency said, as people wept openly in Pyongyang.
KNCA described one of his sons, Kim Jong-un, as the "great successor" whom North Koreans should unite behind.
Pyongyang's neighbours are on alert amid fears of instability in the poor and isolated nuclear-armed nation.
Fears were compounded by unconfirmed reports from South Korean news agency Yonhap that the North had test-fired a missile off its eastern coast before the announcement of Kim Jong-il's death was made.
Unnamed government officials in Seoul were quoted as saying they did not believe the launch was linked to the announcement. The South Korean defence ministry has declined to comment.
Following news of Mr Kim's death, South Korea put its armed forces on high alert and said the country was on a crisis footing. Japan's government convened a special security meeting.
China - North Korea's closest ally and biggest trading partner - expressed shock at the news of his death and pledged to continue making "active contributions to peace and stability on the Korean peninsula and in this region".
Asian stock markets fell after the news was announced.
Crying aloud
Mr Kim's death was announced in an emotional statement on national television.
The announcer, wearing black, struggled to keep back the tears as she said he had died of physical and mental over-work.
The KCNA later reported that he had died of a "severe myocardial infarction along with a heart attack" at 08:30 local time on Saturday (23:30 GMT Friday).
He had been on a train at the time, for one of his "field guidance" tours, KCNA said.
The state news agency said a funeral would be held in Pyongyang on 28 December and Kim Jong-un would head the funeral committee. A period of national mourning has been declared from 17 to 29 December.
Images from inside the secretive state showed people in the streets of Pyongyang weeping at the news of his death.
Ruling party members in one North Korean county were shown by state TV banging tables and crying out loud, the AFP news agency reports.
"I can't believe it," a party member named as Kang Tae-Ho was quoted as saying. "How can he go like this? What are we supposed to do?"
Another, Hong Sun-Ok, said: "He tried so hard to make our lives much better and he just left like this."
KCNA said people were "convulsing with pain and despair" at their loss, but would unite behind his successor Kim Jong-un.
Comments
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