ROME — Italian voters have turned their backs on former Prime Minister Silvio Berlusconi’s conservative party in local elections, according to returns, sending a strong message of discontent by backing a protest movement headed by an irascible comedian turned politician.

The elections were held on Sunday and Monday in nearly 1,000 cities with 9.2 million eligible voters. While local issues dominated, the vote was closely watched as a bellwether of perceived impatience with traditional politics, and analysts concurred that the returns amounted to a strong protest vote.

Much of it was aimed squarely at Mr. Berlusconi’s party, the People of Liberty. After the first round of voting, whose final results were released on Tuesday, the party managed to hold on to only 2 of 17 principal cities it had governed. Although run-off elections in two weeks will ultimately determine the winners, the center-right clearly lagged in many major races.

The most striking result was the strong showing of the Five Star Movement, a grass-roots group that advocates exiting the euro and is led by Beppe Grillo, a comedian and self-proclaimed muckraker. His candidates ran campaigns that spoke directly to citizens.