ROME, March 1 (Xinhua) -- Continuing subzero temperatures from north to south are causing significant agricultural damage in Italy, Coldiretti farmers association said Thursday.

At least 20 percent of the vegetable harvest has been lost, Coldiretti tweeted, citing "frozen fields...and the nefarious effects of bad weather".

The Mediterranean country has been grappling with a Siberian cold front that struck at the beginning of the week, covering the peninsula with ice and snow, causing schools to shut down and plunging transportation networks -- airports, trains, and highways -- into chaos.

The damage to farms could exceed 300 million euros (365 million U.S. dollars) based on past experience, namely the last Siberian cold wave of 2012, according to Coldiretti estimates.

Prolonged subzero temperatures, ice and snow are causing direct damage to produce in the fields as well as indirect damage due to transportation delays, Coldiretti said.

The Civil Protection Agency issued weather alerts and possible flood or landslide warnings due to "prolonged rain, snow and freezing temperatures" from north to south, lasting into Thursday.

Private railway company Italo has cancelled 12 train connections and ferry service has been suspended to some of Italy's islands, RAI News24 public broadcaster reported.