Islamic State supporters, facing regular bans and blockages on Facebook and other social networks, have launched their own CaliphateBook to spread their militant message over the Internet. The site 5elafabook.com, which resembled Facebook but appeared unfinished, went live on Sunday then went offline again a day later and its linked Twitter account was shut down. A message in English posted on its front page said it had temporarily suspended operations to "protect the information and details of its members and their safety". Islamic State, which had declared its own caliphate in territory captured in Iraq and Syria, has relied heavily on social media to spread messages and publicize military victories and its beheadings of prisoners. But mainstream social media companies have raced to remove links to footage of killings -- and many governments have called for stronger restrictions on militants' use of the Internet. It was unclear who created 5elafabook.com -- a name based on an English transliteration of the Arabic word for caliphate 'khelafa' -- or how many members it attracted. The message posted on the front page said it was independent and not sponsored by Islamic State.