All flights will be cancelled except two domestic services a day between Rome and Palermo or Catania, after Italy's national transport minister signed off on Monday on a request by Sicily's regional president to cut off transport links.
A single train to Rome will run each day, while only cargo boats will operate. Passenger ferries and road links – which depend on ferries to make the crossing – are halted.
People who commute across the Strait of Messina for work will still be allowed to do so, as will anyone who can prove they need to travel for health reasons or an urgent, demonstrable need.
Police will be stepping up controls on anyone who crosses into Sicily, including those transporting cargo.
Boats and lorries carrying supplies will continue to circulate.
Waiting to enter a supermarket in Messina. Photo: Giovanni Isolino/AFP
Regional president Nello Musumeci requested the precautions after warning that “more than 31,000 people” had travelled to Sicily in a matter of days.
The concern across much of southern Italy, which has reported far fewer cases of coronavirus than northern Italy, is that people who have left the poorer southern regions to work in the north will attempt to travel to their hometowns or holiday houses to wait out Italy's nationwide quarantine.
If returnees bring the new virus with them, underfunded health services in the south would struggle to cope with an outbreak.
Sardinia, Italy's second biggest island after Sicily, cut off most passenger travel from the mainland on Saturday, except for those who can prove it is essential. Until March 25, any passengers entering or leaving the island must apply for permission at least 48 hours in advance.
As of Sunday evening Sicily had had 188 cases of the COVID-19 virus, including two deaths. Sardinia has had 77 cases and two deaths.