The BBC Arabic account on Twitter also appears to have been hacked by the Syrian Electronic Army, a cyber group that supports Syrian President Bashar al-Assad.
More top news
Karl, 17, was stabbed to death when his friends became involved in a row with around a gang of youths in Hackney, east London in 2004.
Researchers believe they have found the wreckage of British explorer James Cook's ship "Endeavour".
Four kittens have been rescued from a fire by emergency services in California, USA.