North Korean border guards have detained two female US journalists who were filming the communist state from the Chinese side of the frontier, a South Korean television station reported on Thursday.
YTN quoted a Seoul official as saying the guards crossed the border at the Tumen River into Chinese territory to arrest the two on Tuesday after they ignored warnings to stop the filming.
It said the Korean Americans were employed by an online news company based in California but had no other details.
Munhwa Ilbo newspaper separately reported the arrest of a US journalist surnamed Ming but said the incident took place along the Yalu river, which also marks the border.
It said US and North Korean authorities were holding talks about her release.
A US embassy spokesman in Seoul referred inquiries to the State Department, which had no immediate comment.
South Korea's foreign ministry said it would not comment "because this is a matter between the US and North Korea."
The incident comes at a sensitive time in US-North Korean relations, with the communist state preparing what it calls a satellite launch early next month.
The US and South Korea say the launch is a cover for a test of the North's longest-range missile, in violation of a UN resolution passed after its missile and nuclear tests in 2006.
The North is also angry at an ongoing US-South Korean military exercise that it describes as a rehearsal for an invasion.
It has told the United States it no longer wants to receive food aid, according to the State Department on Tuesday.
Five US non-governmental organizations distributing food said their 16-member team would be leaving by the end of the month, two months earlier than scheduled.
Journalists who wish to visit North Korea must obtain special visas and are accompanied by official guides during their stay. Few such visits have been allowed in recent years.
The North has, in the past, freed Americans it has detained..
Then-US congressman Bill Richardson in 1996 negotiated the release of US citizen Evan Hunziker, who was detained for three months on suspicion of spying after swimming the Yalu river.
Richardson, who is now New Mexico governor, at the time described Hunziker as a confused young man who engaged in an "adventuresome frolic apparently under the influence of alcohol."
In 1994 Richardson helped negotiate the released of a US military helicopter pilot shot down after straying into North Korea.