Counting is under way after Lebanese voters flocked to the polls in an election in which a Hezbollah-led coalition was aiming to seize the parliamentary majority from a Western-backed alliance.
The first official results from Sunday's general election were expected within hours of the official end of polling at 7pm local time (16:00 GMT), with the Christian districts expected to decide the outcome.
Al Jazeera's James Bays, reporting from El Metn, said that unofficial results from four districts suggested that the race was "extremely close".
He said that the unofficial results from Keserwan, Zghorta, Becharre and Batroun appeared to have been agreed on by the two main alliances and showed them running almost neck-and-neck.
However, Samir Geagea, the Christian leader of the Lebanese Forces party, predicted that the current ruling parliamentary majority would be returned.
"In my opinion, yes, March 14 ... will return as the majority," he told local LBC television.
Future TV, the station owned by Saad al-Hariri, the leader of the March 14 bloc, also predicted its victory saying it was expected to win 70 seats to 58 for the Hezbollah and its allies, including the Free Patriotic Movement, headed by Michel Aoun, a Christian leader and former military chief.
However, a Hezbollah official told Al Jazeera that ballots were still being counted and they were not conceding defeat at this stage.
Long queues had formed outside polling stations during the day, with some people complaining that they had to wait for up to three hours to cast their ballots.
Lebanon's interior ministry said turnout was more than 52 per cent, exceeding the 45 per cent total recorded in the 2005 election.
"Since 1990, and possibly even before, we have not seen such turnout," Ziad Baroud, Lebanon's interior minister, said.
"The election was a challenge that many doubted would take place. But Lebanon's political factions and the Lebanese met the challenge."
Al Jazeera's Todd Baer, reporting from Beirut, said that the high turnout was "surprising and extraordinarily encouraging".
"You have the sense here that people really felt like their vote was going to count for the first time in a long time," he said.
It is the first time that a Lebanese election has been held on a single day rather than over a month.
Most analysts believe that Lebanon's complex political system will lead to a unity government including elements of the March 14 bloc, which currently holds the parliamentary majority.
The country's president must be a Maronite Christian, the prime minister a Sunni Muslim and the speaker of parliament a Shia Muslim.
The 128 seats in parliament are divided equally between Christians and Muslims.
Christians could could the key to the next Lebanese government, with Aoun challenging Geagea's Lebanese Forces and the Phalange party led by Amin Gemayel, a former president and another member of the March 14 camp for their votes.
Baroud said that the highest turnout had been reported in the Christian districts, with Keserwan at 70 per cent and Metn, Batroun and Jbeil at 60 per cent.
Polling day was largely peaceful with more than 50,000 soldiers and police deployed across the country.
However, a shooting was reported outside the headquarters of Future Television.
No one was injured in the shooting when a group of men opened fire from a car as it drove by.
There were also reports of brawls between rival supporters in several areas of Beirut and a shooting in Tripoli.