The island's Catania international airport, known as Catania–Fontanarossa Airport, was to be closed until at least 8pm (4am AEST) on Monday following the eruption of nearby Mount Etna, the airport press office said in a statement.
"All arrivals and departures are therefore prohibited," the statement said, adding that "passengers are kindly requested to present themselves at the airport only after consulting their airline".
The volcanic activity, which began late on Sunday (early Monday AEST), evolved into a "lava fountain", producing a volcanic cloud dispersed in a southerly direction, according to the Italian National Institute of Geophysics and Volcanology's Etna observatory.
This is "producing a fallout of ash in the southern sector of the volcano and beyond", it said.
Several flights scheduled to arrive in Catania, including those from destinations such as Malta, France, Austria, and other Italian regions, have been cancelled, delayed, or diverted, according to flight-tracking service Flightradar24.
The closure comes just days after the airport resumed operations, having been disrupted by a major fire in its terminal building in mid-July.
As well as being the most active, Mount Etna is Europe's highest volcano, at about 3350 metres tall.
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