ZAGREB, May 27 (Xinhua) -- The ruling center-right Croatian Democratic Union (HDZ) can't be pleased after winning only four seats in the European Parliament elections on Sunday, the same amount as the main opposition Social Democratic Party (SDP), politicians and analysts commented on Monday after the final results were announced.

"I am not happy with the election results," said Croatian Prime Minister Andrej Plenkovic who is also HDZ president in the early morning hours on Monday.

The ruling party was expected to win during Sunday's elections five or even six seats out of the 12 the country is allocated in the European Parliament.

Ruza Tomasic, member of the right-wing Sovereignist coalition, and Mislav Kolakusic, a former judge, each won a seat. Anti-establishment and populist party Living Wall (Zivi zid) and the liberal Amsterdam coalition also secured one seat each.

For SDP, the biggest opposition party in the southeastern European country, Sunday's success was a surprise. Party leader Davor Bernardic gave an emotional speech after he realized that the SDP won four seats, one more than expected.

"This is the beginning of the much-needed changes in Croatia," Bernardic said. At least for the moment, the latest success has invigorated the party that is hit by internal divisions and whose support has been falling in the recent months.

"The elections result in Croatia follow European trends, which means that the left is weakened, and the rightist parties and populists are strengthened," analyst Zarko Puhovski told Xinhua.

He believes that the HDZ has failed because the party had expected at least five seats. The party was supported by German Chancellor Angela Merkel who came to its final meeting in Zagreb on May 18, but even her visit didn't help the results.

Although the HDZ got the most votes in the elections and won in 13 counties, it scored the worst result in recent years and secured only 21 percent of the votes in Croatian capital Zagreb.

The SDP won in four largest cities in Croatia, namely Zagreb, Split, Rijeka and Osijek. It pledges to strive for higher salaries and pensions for the better life of all.

After the success of Ruza Tomasic, the right-wing parties in the country announced to join forces in the parliamentary elections next year.

The biggest surprise from Sunday's elections is the success of the former judge of the Commercial Court in Zagreb, Mislav Kolakusic, who announced to run in the presidential elections to be held at the end of this year.

The Living Wall party, after winning one seat in the elections, announced that it has collected 375,000 signatures to organize a referendum on whether the state should finance the work of political parties.

A total of 29.6 percent of Croatia's 3.8 million voters went to the polls on Sunday, nearly five percent more than in the last elections in 2014.