'We're aware of reports that early in the morning of March 17, China time, two American citizens were taken into custody across the Tumen river by what appear to be North Korean border guards,' State Department press officer Fred Lash said.

'We are working with Chinese government officials in that particular area to ascertain the whereabouts and welfare of the Americans in question,' he added.

'We've also been in touch with North Korean officials to express our concern about the situation,' said Mr Lash.

Washington had also been 'in touch with our protective power (in North Korea), the Swedish embassy in Pyongyang.'

Mr Lash said that he did not have the names of the journalists concerned, nor any details about who they worked for.

State Department spokesman Robert Wood had little to add during the daily news media briefing and could not confirm that US officials had yet been in contact with the Swedish embassy.

'We're trying to ascertain all of the facts. We do know that these two Americans were taken into custody,'

'I really don't have any real definitive information for you, no real independent information other than what we've seen in the reports, and we're busily trying to gather more details,' Mr Wood said. -- AFP