Transcript for Bold daylight jewelry heist occurs in London

No reason why that went down. The manhunt at this hour after a bold heist in daylight. Using hammers to smash their way in, and then one waving a sledgehammer on their way out. ABC's James Longman from London tonight. Reporter: Tonight, London police searching for the mysterious thieves in this daring jewelry heist. This video capturing them pour out of the smoke-filled shop, one after another, five figures in black still wearing their helmets, they jump on to their waiting mopeds, making a speedy getaway. You can see one of the thieves wave a sledge hammer used to smash their way in and inside, the aftermath another hammer discarded. The thieves taking an unknown amount in valuables from the display cases. You can see they have put the glass back on that shop now. This happened right in the middle of central London, we're just around the corner from the famous department store, harrods. And this is not the first heist of its kind. In April, 2015, the biggest heist in uk history, nearly $20 million was stolen from a safety deposit box by four elderly pensioners. There's no indication of any connection to other robberies. No one was hurt, police haven't made any arrests yet but are appealing for witnesses.

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