Washington - The United States is seeking the release of two American journalists who were arrested by North Korean authorities along the Chinese border, the US State Department said Thursday.

"It's our concern when you have ... two American citizens who are being held against their will," US State Department spokesman Robert Wood said. "We want to try to find out all the facts and try to ... gain their release."

Wood was unable to provide details about the journalists or the circumstances surrounding their detention, but said Washington was working through the Chinese and other diplomatic channels to gather more information.

The two women were identified by The New York Times as Chinese American Laura Ling and Korean American Euna Lee. They work for a US-based Current TV, a channel co-founded by former vice president Al Gore.

The United States and North Korea do not have formal diplomatic relations, but communicate through the Swedish embassy in Pyongyang and the United Nations in New York.

South Korean media reported the journalists were detained earlier this week by North Korea border guards while filming along the border with China. There have been contradictory reports about whether the women crossed into North Korea or the guards detained them on Chinese territory.

   Chinese Foreign Affairs Ministry spokesman Qin Gang said China was unable to determine on which side of the border the incident occurred.

   "The Chinese government is investigating what happened to the two American citizens on the border between China" and the Democratic People's Republic of Korea, Qin told reporters in Beijing.

The New York Times reported that a South Korean Christian ministry, Durihana Mission, helped the women arrange their trip to China. The group's minister, Chun Ki Won, told the newspaper that he had spoken to the journalists earlier in the week and was informed they were reporting on North Korean refugees in China.

   "I warned them against getting too close to the border," Chun said. "I suspect that they got too ambitious."