N Korean leader tours Russian nuclear centre

The North Korean leader, Kim Jong Il, has visited a Russian nuclear research centre in the Siberian city of Novosibirsk.

The visit to the Budker Nuclear Physics Institute was closed to journalists and marked by the heavy security which has surrounded the whole of Mr Kim's tour of Russia.

Mr Kim made the visit on his way back to North Korea across Russia in an armoured train.

Last week, Russia and North Korea signed a joint declaration stating that Pyongyang's missile programme was not a threat to anyone - as long as North Korean sovereignty was respected.

From the newsroom of the BBC World Service