CHENGDU - Thousands of travelers were stranded Tuesday in Southwest China's Sichuan province as heavy fog forced authorities to shut down a dozen highways and a regional airport for more than seven hours.

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The Shuangliu Airport in Chengdu city, the provincial capital, was closed from 3 am to 10:20 am, delaying 110 departure and arrival flights there, said officials with the regional aviation authority.

Six flights were canceled, officials said, and nearly ten thousand air travelers were stranded at the airport.

Heavy fog hovered over most parts of the Sichuan Basin, and east of the Qinghai-Tibetan Plateau Tuesday, the provincial weather forecast bureau said. Half a dozen cities in the area issued travel warnings.

Eleven highways in Sichuan were closed Tuesday morning but all had reopened to traffic by 1 pm, local officials said.