Israeli Prime Minister Benjamin Netanyahu (L) casts his ballot at a polling station in Jerusalem, April 9, 2019. Israel on Tuesday morning started day-long general elections across the country to choose its next parliament and decide the premiership. (Xinhua/JINI/Emil Salman)

Exit polls of the Israeli elections on Tuesday show a race too close to call, where leaders of both rival parties have declared victory.

Incumbent Prime Minister Benjamin Netanyahu, leader of the Likud Party, announced "a clear-cut victory" on his Facebook page, while the former military chief Benny Gantz, leader of the Blue and White party, tweeted "We have won!"

The three leading exit polls showed different breakdowns for possible coalitions after the elections, but one common denominator was the advantage of Netanyahu in leading the right-wing bloc which had more seats than the rival center-left bloc.

Initial official results are expected in the early hours of Wednesday morning, where several more parties, allied with either side, may have the chance to cross the 3.25-percent threshold to change the political landscape.

"The picture right now is completely unclear. There are possible scenarios in which neither of the big parties are able to form a coalition," said Julia Elad-Strenger of the Department of Political Sciences at Bar Ilan University.

"The center-left bloc will have a very difficult time in creating a coalition. But the right bloc will also have difficulty," said Oded Eran, a senior researcher at the Israeli Institute for National Security Studies.

While the Likud has won 33 to 36 seats, there are several small right-wing parties that Netanyahu will need in order to form a coalition. This might increase the pressure on him to pay a high political price for leading the next government.

"It may seem theoretic at this point, but the Likud and Blue and White may even form a coalition together," Eran, also a former senior Israeli diplomat, told Xinhua.

Another element that may also tip the balance is Israeli soldiers who are expected to vote in the early hours of Wednesday.

"Soldiers tend to be more right-wing," Elad-Strenger explained. "They can move parties above the threshold and change the whole picture completely."

Notably, the final results are expected on Thursday at the earliest, as the neck-to-neck race makes every single vote count.

In addition, the ongoing elections are widely perceived in Israel as a referendum on the decade-long consecutive ruling of Netanyahu, who is fighting to avoid being indicted in at least three separate cases of bribery, fraud and breach of trust.

Israel's attorney general is expected to hold a hearing for Netanyahu in the summer, after which he will decide whether Netanyahu will be indicted. Should the indictment decision be made, there will be likely mounting pressure on Netanyahu to resign, which will lead Israel to another general elections in no more than a year.

But "the corruption allegations proved to be not such a major consideration among voters," Eran noted.

Should Netanyahu succeed in leading the next government, he will become the longest-serving Israeli prime minister this summer. However, the road to his fifth term in office will not be easy.

"The coalition negotiations will take a very long time. The small parties are going to be tough negotiators," Eran noted.