ROME, Dec 14 (Reuters) - Italy on Tuesday extended a COVID-19 state of emergency to March 31 and ruled that all visitors from EU countries must take a test before departure, amid concerns over the spread of the Omicron variant of the coronavirus. The state of emergency, which was introduced in January last year, gives greater powers to the central government, making it easier for officials to bypass the bureaucracy that smothers much decision-making in Italy. It was set to expire at the end of December. The Health Ministry"s decision to impose a test on people arriving from European Union countries from Dec. 16 to Jan. 31 extends a requirement which was already in force for many non-EU countries. Those who have not been vaccinated must also undergo a quarantine of five days on arrival. The decision met with the disapproval of the European Commission, which favours common rules to travel within the bloc based on a so-called Green Pass certificate proving vaccination against the virus. "These individual decisions of the member states will damage ... the trust of the people that there are equal conditions everywhere in Europe," Commission vice president Vera Jourova told a news conference in Brussels. Italian tour operators also expressed their disappointment. The Organised Tourism Federation said the tougher rules were "a fresh blow" to the hard-hit sector and called on the government to provide "immediate and adequate compensation". Italy"s daily coronavirus infections are rising steadily, with 20,677 new cases reported on Tuesday, and 120 deaths. Pressure on hospitals remains less acute than in nearby countries such as Austria and Germany, where the rise in cases in the so-called "fourth wave" of the pandemic began earlier. Italy has so far reported 27 confirmed Omicron variant cases, the European Centre for Disease Prevention and Control (ECDC) said. Italy has registered 135,049 deaths linked to COVID-19 since February 2020, the second-highest toll in Europe after Britain and the ninth-highest in the world.