ZAGREB, Croatia (AP) — The candidate of a leftist-green group has taken a strong lead in voting for the mayor of Croatia’s capital, Zagreb, dealing a blow to the ruling conservatives, preliminary official results on Monday showed.

Tomislav Tomasevic garnered around 48% support in Sunday's vote, while his “Mozemo!” or “We Can!” coalition won the most seats in the capital city's assembly.

The result is a setback for the ruling Croatian Democratic Union, which had hoped to win in Zagreb after the death in February of long-serving mayor Milan Bandic. Tomasevic will face a right-wing opponent, former singer Miroslav Skoro, in a runoff vote in two weeks.

Croatia’s 3.6 million voters also chose hundreds of municipal and city councils, as well as district authorities throughout the European Union nation.

Another round of voting will also be held in three other key towns — Split, Rijeka and Osijek — where no mayoral candidate won an outright majority. The conservatives' candidate is in the lead in the eastern town of Osijek while opposition politicians are ahead in the coastal towns of Split and Rijeka.

Prime Minister Andrej Plenkovic said his HDZ remains the strongest party, leading in most local assemblies, mayoral races and regional councils overall. Plenkovic described the election outcome as “victorious.”

In Zagreb, Tomasevic said the results clearly showed that citizens want a change after Bandic's corruption-plagued two decades in power in the city. Tomasevic said that “Zagreb does not belong to an interest group.”

“The citizens said that we can!" he said late Sunday. “We can do greener, more just, more transparent, better!"

One of the best-known politicians in the country, Bandic faced a series of corruption scandals while in office. He was detained in 2014 but was still later re-elected to the post.