Croatia's conservative opposition bloc has taken the early lead over the ruling centre-left alliance in a closely fought election, according to preliminary results based on a partial vote count.

The conservative bloc, led by the HDZ party, was projected to take 60 seats in the 151-seat parliament, while the Social Democrat-led governing alliance was projected to take 55 seats, according to results based on votes from nearly 27 percent of Croatia's 6,500 polling stations on Sunday.

The partial count projected that another 19 seats would go to the new political party, Most, which is likely to play a crucial role in negotiations over the formation of a government.

Croatia and Serbia fight over the handling of refugees

The remaining nine seats would be shared by four minor parties, while eight seats are reserved for minorities.

The HDZ, now led by ex-spy chief Tomislav Karamarko, was ousted from power four years ago amid a series of unprecedented scandals involving its former leader and ex-Prime Minister Ivo Sanader.

But the centre-left government at the helm since then has disappointed voters by failing to reform the public sector and boost the business climate, although Croatia saw a slight return to economic growth this year after six years of recession.

Sunday's election, overshadowed by a wave of refugees passing through the small country, is the first since Croatia joined the European Union in 2013, and it remains one of the bloc's poorest-performing economies.

Al Jazeera's Jasmina Kos said the final results were not expected to be announced until later on Monday, and that dealing with the country's refugee crisis would be a major question for the new government.

"If the ruling centre-left coalition stays for another four years ... they will continue with the humane approach they have been trying to implement," Kos said.

"If the centre-right wins this election, then they will enforce stricter rules on the borders."

Source: Al Jazeera And Reuters