Seoul, South Korea ? Two American journalists detained by North Korean soldiers are believed to have been sent to Pyongyang for questioning, a news report said today.

North Korea said Saturday it was investigating two Americans it detained Tuesday for “illegally intruding” into its territory after crossing the border from China.

South Korean media and a South Korean missionary identified the two detained Americans as Laura Ling and Euna Lee, reporters for former Vice President Al Gore’s San Francisco-based media outlet Current TV.

A U.S. official said Saturday that the U.S. has been in touch with North Korean representatives about the journalists and is awaiting a reply. The official, who spoke on condition of anonymity citing the sensitivity of the issue, said the U.S. doesn’t know where the North is holding them.