Prime Minister Mahinda Rajapakse led presidential balloting Friday with most votes counted. His office declared victory for the leader, a hard-liner toward the nation's separatist rebel insurgency.

The vote count was still under way and no announcement had been made by the election commission.

According to unofficial returns broadcast by Sri Lankan TV channels, Rajapakse had received 4.65 million votes to 4.47 million for opposition leader Ranil Wickremesinghe. Officials estimated that nearly 10 million votes were cast in Thursday's balloting.

"We are confident he will be the president," said the prime minister's brother, Basil Rajapakse, who heads the election campaign.

The Prime Minister's Office appealed to the Sri Lankan people "to behave peacefully and celebrate the victory without harming opponents."

Violence erupted Friday in Akkaraipattu, 140 miles east of Colombo, as suspected rebels tossed grenades into a Mosque during morning prayers, killing at least four Muslim worshippers and wounding 10, police said.

There were no other immediate details of the attack and it wasn't known if it was linked to the voting.

During the election Thursday in the north and east — territory of the feared Tamil Tiger rebels — grenade attacks, roadblocks and fear kept many Tamils from voting. Others heeded a boycott called by pro-rebel groups that complained neither of the main candidates would help them win a homeland in northeastern Sri Lanka.

The Tamils, whose plight is at the heart of a civil war that has lasted more than two decades, make up just under 20 percent of Sri Lanka's 19 million people but were potential kingmakers in the tightly contested election.

The race pitted hard-line Prime Minister Mahinda Rajapakse against dovish opposition leader Ranil Wickremesinghe, whose softer line on peace talks with the rebels won him wide support among Tamils, a largely Hindu minority.

The new president "will have to sort out the country's main ethnic problem," said D. Maulana, 35, who sells auto parts in Colombo. "As all of us know without that, nothing can go forward until it is over."

No polling stations were set up in Tiger strongholds because of security concerns, but the government set up special voting booths on the edge of insurgent territory to accommodate the more than 200,000 voters who live behind rebel lines.

But officials said roadblocks and intimidation had kept most from making it out of rebel territory to vote.

In Jaffna, controlled by the government but heavy with Tigers, rebel supporters hit a Tamil man in the head to keep him from voting. A bus driver who tried to run through a roadblock at a nearby rebel enclave didn't make it and was also beaten.

Turnout was less than 1 percent in and around the northern city — the lowest ever in any of the Indian Ocean country's 22 districts.

Grenade blasts forced European Union observers to pull out of the eastern city of Batticaloa, the scene of frequent clashes between the Tigers and breakaway rebel factions. At least two people were killed in the attacks.

In the Batticaloa district, split between the rebels and government, turnout was 43 percent, down from around 70 percent in the last presidential vote — a drop officials attributed to the fact that few Tamils from rebel areas voted.

Perinban, a 57-year-old Tamil farmer from a rebel area near the eastern village of Vavunathivu, wanted to vote.

But on his way to the polling station he saw a roadblock of burning tires and palm fronds and said he knew exactly what it meant: "Burning tires are a signal that we should not go beyond this."

The Tigers took up arms in 1983 over discrimination against Tamils, most of whom are Hindu, by the predominantly Buddhist Sinhalese majority. Nearly 65,000 people have been killed in the conflict.

A 2002 cease-fire ended major fighting, but peace talks stalled in disagreement over the Tigers' demands for broad autonomy in their northeastern stronghold, and clashes — especially between the Tigers and a breakaway faction — have intensified. The August assassination of Foreign Minister Lakshman Kadirgamar was blamed on the rebels.

Still, the Tigers have not launched suicide attacks like the ones that have disrupted past votes. Outgoing President Chandrika Kumaratunga, who did not run because of a constitutional two-term limit, lost an eye in one such bombing in the 1999 campaign.

Election Commissioner Vanyananda Dissanayake said the overall vote was "largely peaceful and incident-free" compared with past balloting.

Rajapakse, who turns 60 on Friday, has pledged to review the stalled peace process and not share political power or tsunami aid with the Tigers. He insists his hard line can lead to peace — a tough stand that has won him wide support among Sri Lanka's Sinhalese majority.

"I am not a candidate for war ... but it has to be an honorable peace," he said after voting in southern Sri Lanka.

Wickremesinghe, 56, who signed a cease-fire with the rebels in 2002 when he was prime minister, voted in Colombo. He promises to strike a peace deal by granting Tamils a degree of autonomy. He also favors further liberalizing the economy.