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US tightrope walker Nik Wallenda has successfully completed back-to-back high-wire walks above the city of Chicago, watched by thousands of people.

The 35-year-old achieved the two skyscraper crossings without a safety net or a harness.

He first walked up a steep incline between buildings either side of the Chicago River.

Then, blindfolded, he crossed between the two Marina City towers.

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It took him six minutes 52 seconds to complete the first stage 500ft (152m) above the ground - in winds that were gusting at up to 25mph (40km/h).

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He then completed the 94ft between the two Marina City Towers in one minute 17 seconds.

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The stunts were televised with a 10-second delay in case he fell.

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On the ground, thousands cheered Mr Wallenda - a seventh-generation tightrope walker.

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Mr Wallenda - again blindfolded - then answered reporters' questions. He has already walked across both the Grand Canyon and the Niagara Falls on tightropes.