Police in the United States have charged a man with using an Internet chat room to try to set up a mass suicide pact for Valentine's Day.

Officers are now trying to use computer records to trace dozens of potential participants in the US and Canada, to ensure they are safe.

26-year-old Gerald Krien from Klamath Falls, Oregon, was charged with trying to solicit aggravated murder.

Police said the participants apparently planned to log on to the chat room on 14 February and commit suicide while in touch over the Internet.