Exit polls in Israel's election suggest Prime Minister Benjamin Netanyahu's Likud party and the Zionist Union are neck-and-neck
Two polls project the parties have 27 seats each, while a third says Likud has one more seat than its rival, led by Yitzhak Herzog
Mr Netanyahu hails the outcome as a "great victory" for Likud, but Mr Herzog insists "everything is open"
Both would need the support of other parties in the 120-seat Knesset to form a coalition government
The exit polls suggest that the Joint List, an alliance of Arab-Israeli parties, has come third (All times in GMT)
Voter turnout was 71.8%, according to Israel's Central Elections Committee. That is 4% more than in the 2013 election, and the highest turnout since 1999, according to Israel's embassy in the US.
Kevin Connolly
BBC News, Tel Aviv
What had looked like a rather panicked and rather desperate tragedy in the last 48 hours - Benjamin Netanyahu suddenly being wheeled out to do interview after interview, warning of what he called the dangers of a leftist victory - suddenly appears to have paid off.
Mr Netanyahu has hailed a "great victory" for Likud - but not everyone agrees with him. Maya, a supporter of the Zionist Union, tells the BBC's Mark Lowen in Tel Aviv: "I don't think that we have finished our judgment yet. It's all about who will be able to form the biggest coalition now."
Israeli media report that Foreign Minister Avigdor Lieberman, leader of the right-wing Yisrael Beiteinu party, has refused to take calls from Mr Netanyahu and Mr Herzog.
Although the exit polls show Benjamin Netanyahu's Likud party tied with Yitzhak Herzog's Zionist Union with 27 seats each, correspondents say the prime minister will have an easier time forming a coalition with a majority in the 120-seat Knesset. Mr Netanyahu has already begun to call potential partners.
Israel President Reuven Rivlin has said he will work for a national unity government, the Haaretz newspaper reports. It quotes Mr Rivlin as saying that "only a unity government can prevent the rapid disintegration of Israel's democracy and new elections in near future".
Here is the full translation of Mr Netanyahu's tweet from the Reuters news agency: "Against all odds: a great victory for Likud, a great victory for the national camp led by Likud, a great victory for the people of Israel."
Image source, AFPOn Twitter, Benjamin Netanyahu writes in Hebrew, external that he is celebrating a "great victory".
As for the newcomer, the former Likud minister Moshe Kahlon and his Kulanu party - it looks likely it will gain either nine or 10 seats.
Image source, EPAA quick update on one of the other candidates: Yair Lapid, and his centrist Yesh Atid party. All the exit polls put the former broadcaster's party in fourth place - with either 12 or 11 seats. That would represent a step back from the 19 won in 2013 - but Mr Lapid may yet have a crucial role to play in forming a governing coalition.
Image source, ReutersMichael Shuval
Producer, BBC Arabic
tweets, external: 1st reax from @ZionistUnion: Likud is misleading. Right bloc shrunk. All open until final results come in & we'll know what gov we can form.
The Times of Israel says, external the two leading figures in the Zionist Union, Labour's Yitzhak Herzog and Tzipi Livni of Hatnua, are locked in talks. Mr Herzog is expected to address supporters at the Zionist Union's election headquarters in Tel Aviv within the next hour.
Image source, ReutersA spokesman for the Likud party tells the BBC's Kevin Connolly: "There was some concern in recent days but I think we are all feeling a celebratory mood with these polls." He adds: "There's no 100% certainty, but I feel confident that the prime minister will continue to lead the government."
Twenty-five minutes ago, exit polls from Israel's election were released. They suggest Prime Minister Benjamin Netanyahu's right-wing Likud party and the centre-left Zionist Union are neck-and-neck. Two TV stations project that the parties will win 27 seats each, while a third says Likud will win one more seat than its rival. The exit polls suggest that the Arab Joint List, an alliance of Israeli Arab-dominated parties, will come third with up to 13 seats.
Image source, APZionist Union supporters react as the first exit polls are released at the alliance's election headquarters in Tel Aviv
Lahav Harkov, a senior Knesset reporter with the Jerusalem Post, tweets, external from Likud's headquarters: "In the last election, Likud has a much bigger lead and Likudniks were sad. Now they're tied and everyone is jumping for joy."
Anshel Pfeffer, a journalist with Haaretz newspaper, tweets, external: "Herzog almost certainly didn't win tonight but at he did a lot better than anyone expected just a couple of weeks ago. Still a contender."
Mark Lowen
BBC News, Tel Aviv
tweets, external: Abigail: Zionist U, Danny:Likud. Both disappointed by exit polls. "Nobody seems to have won tonight" #IsraelElections
Image source, Mark LowenAs expected, it looks as though the Arab Joint List might have finished third. Exit polls suggest the alliance will win 13 seats. It has said, however, that it will not take any positions in government.
Michael Shuval
Producer, BBC Arabic
tweets, external: Likud supporters chanting at party's headquarters: "Bibi is the next Prime minister"
Image source, Michael ShuvalThe final results from the election are not expected until early on Wednesday morning.