North Korea has started sending troops to fight with Russia in Ukraine, South Korea's spy agency has said as Seoul warned of a "grave security threat".

The allegation comes a day after Ukrainian President Volodymyr Zelensky said he believed 10,000 North Korean soldiers could join the war, based on intelligence information.

South Korean President Yoon Suk Yeol called for a security meeting on Friday and said the international community must respond with "all available means".

According to the spy agency, 1,500 troops have already arrived in Russia - with anonymous sources telling South Korean media the final figure could be closer to 12,000.

Subscribe here: http://bit.ly/1rbfUog

For more news, analysis and features visit: www.bbc.com/news

#NorthKorea #Russia #BBCNews