Italian broadcaster RAI has shown footage purporting to show the rescue operation underway off the coast of Sicily.
What appears to be the hull of a boat is visible under the green and red vessel.
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People who voted remain in the EU referendum have gathered at a protest in London to ask the government to make a plan.
Gunshots and explosions have been reported at Istanbul's Ataturk Airport.
Police say they are keeping an open mind about the motive and appealed for anyone with information to come forward.