North Korean leader is in grave danger, reports say

The US is monitoring intelligence that suggests North Korea's leader, Kim Jong Un, is in grave danger after undergoing a previous surgery, according to a US official with direct knowledge.

A second source familiar with the intelligence told CNN that the US had been closely monitoring reports on Kim's health.

Kim recently missed the celebration of his grandfather's birthday on April 15, which raised speculation about his well-being. He had been seen four days before that at a government meeting.

Daily NK, an online newspaper based in South Korea that focuses on North Korea, reports that Kim reportedly received a cardiovascular system procedure on April 12.