A US man has been charged with using an internet chat room to try to set up a mass suicide pact for Valentine's Day.
Krien is expected to appear in court next week
Police are now trying to use computer records to trace dozens of potential participants in the US and Canada.
Gerald Krien, 26, from Klamath Falls, Oregon, was charged on Friday with trying to solicit aggravated murder.
Police were alerted by a Canadian woman who became worried after learning that a mother planned to kill her two children before killing herself.
If convicted, Mr Krien could face 10 to 30 years in prison.
The participants - as many as 32 - apparently planned to log into the chat room on Valentine's Day and commit suicide while in touch over the internet, police said.
Investigators are examining Mr Krien's computer and webcam to determine whether the agreement was genuine or a hoax.
Klamath County sheriff Timothy Evinger said the priority was to establish where any people at risk - particularly the children - were located.
"Hopefully we can intervene if anyone still has the notion to follow through with this," he told the Associated Press news agency.
Police said there did not appear to be any religious motivation for the pact. The chat room was designed for people interested in suicide.
District Attorney Ed Caleb said he is taking the messages seriously.
"There is always a chance this is a joke, but our position is in this world, any time a person makes these kinds of overt actions, they need to be looked into," said Mr Caleb.
Mr Krien, who lives with his parents, is expected to appear in court next week.