Israeli election officials reported the lowest turnout among voters in the state's 54-year history in Israel's general election on Tuesday.

Just over half the number of eligible voters had cast their ballot hours before polls were due to close at 2200 local time (2000 GMT), according to the Israeli Central Elections Committee.

If we don't succeed this time, we will continue to be an alternative in the future Amram Mitzna, Labour Party leader

Click here for Mitzna profile

Exit polls are expected almost immediately afterwards, with incumbent Israeli Prime Minister Ariel Sharon forecast to return to office by a comfortable margin.

As Israelis voted, four Palestinians were killed by Israeli gunfire in the West Bank city of Jenin, according to Palestinian security sources.

The election is taking place amid tight security, with tens of thousands of Israeli police and soldiers deployed across the country.

Israel has also closed the West Bank and Gaza Strip until after the elections, amid fears of attacks by Palestinian militants.

Coalition building

Opinion polls in Israeli newspapers suggest Mr Sharon's right-wing Likud Party will emerge as the largest faction, surging from its current 19 seats to 32 or 33 places in the 120-member Knesset (Israeli parliament).

ISRAELI ELECTIONS

4.8m voters Voting by proportional representation 27 parties vying for 120 seats

Click here for a guide to the election process

The opposition Labour Party, whose withdrawal from the coalition government in October 2002 precipitated the election, looks set to suffer its worst result since the first Israeli elections in 1949.

Mr Sharon's tough approach towards dealing with the Palestinians appears to have won over many voters frightened and tired by a seemingly endless conflict.

Nevertheless, to go into government he will need to put together a coalition - either with Jewish religious and ultra-nationalist parties on the right-wing, or with secular parties from across the political spectrum.

The BBC's Jeremy Cooke in Jerusalem says the only certainty is that there will be days, perhaps weeks, of intensive political horse-trading before Israelis learn the composition and the policies of their new government.

Casting his vote at a Jerusalem high school, Mr Sharon said: "I hope this will be the last time we will have elections in the next four years."

The ballot is Israel's fourth since 1996. No Israeli government has served its full term since 1988.

Labour loss

Labour Party leader Amram Mitzna has refused to join any coalition with Likud - "a promise is a promise", he said on Monday - and appeared resigned to defeat.

We should .... move forward. We need a national unity government Ariel Sharon

Click here for more on Ariel Sharon

"If we don't succeed this time, we will continue to be an alternative in the future," he said.

In contrast to Mr Sharon, Mr Mitzna argues that negotiations are the only way to stop the violence with the Palestinians, along with separation of the two communities and an eventual Palestinian state.

But this does not seem to have impressed the voters, with a whole series of opinion polls showing support for Labour draining away.

Labour, which currently holds 25 seats in the Knesset, is likely to drop to 18 or 19 seats.

With the main parties' fortunes seemingly sealed, the centrist, staunchly secular Shinui Party has emerged as a possible kingmaker.

Led by Tommy Lapid, a 71-year-old former journalist and Holocaust survivor, Shinui is predicted to win 15 or 16 seats and replace Shas as the third-largest party.

Mr Lapid has urged Labour to join a coalition government with Shinui and Likud, and deny the religious parties the balance of power.