A Facebook advert launched by Derbyshire police has been viewed more than 400,000 times.
The site appeals for more information about a house fire in Derby in which six children died.
670 people have also clicked through to the Derbyshire Constabulary website for more information.
A team of 60 police officers are working to find those responsible for an arson attack which killed six children in Derby two weeks ago.
Inquests will open this morning into the deaths of six children who died in a house fire in Derby a week ago.
Mick and Mairead Philpott addressed the media today following a house fire that killed six of their children.