ROME, December 1 (RIA Novosti) - Italy's famous lagoon city Venice, along the northeastern Adriatic coast, was flooded on Monday as high tides pushed sea levels to the highest in the past 30 years, the ANSA news agency said.

Around 40% of the city's historic buildings are reported to have been affected, while authorities are warning that sea levels could rise 1.6 meters (5ft 3in) higher than normal, swamping some 90% of the city.

St Mark's square in the city's historic center is reported to be submerged under 80 cm (2ft 7in) of water, the news agency said.

The news agency also said Venetians were equipping themselves "with thigh-high boots of the kind fishermen wear."

The city mayor, Massimo Cacciari, has advised residents to stay at home.