BIKFAYA, Lebanon, (AP) – Lebanon’s opposition captured one of two parliament seats up for election Sunday to replace assassinated ruling party lawmakers in a tense showdown between the U.S.-backed government and opponents supported by Syria and Iran.

The government coalition retained the second seat virtually unopposed, according to official results

Although the vote was for just two of the 128 seats in parliament, it could affect the political future of this deeply divided nation by influencing who lawmakers elect as president later this year.

Lebanon’s government and the opposition — led by the Islamic militant Hezbollah — have been locked in a fierce power struggle. The choice of a new president could tip the balance in favor of one or the other.

The voting was largely peaceful although a few skirmishes between the rival camps were reported.

Voters picked candidates to replace Pierre Gemayel, a Christian who was shot dead in November, and Walid Eido, a Sunni Muslim killed in a Beirut car bomb in June. Both were vocal opponents of neighboring Syria, which controlled Lebanon for 29 years until it was forced out in 2005. Gemayel was also a cabinet minister.

The key vote was a bitter contest in the Metn region, a Christian stronghold northeast of Beirut. Amin Gemayel, a former president from 1982-88 running on behalf of the government for a seat his son held before his assassination last year, faced Kamil Khoury, a political newcomer supported by Christian opposition leader Michel Aoun. Aoun is a former army commander and interim prime minister allied with the opposition.

The government said its coalition lost the seat by a small margin. Interior Minister Hassan Sabei, announcing the results before dawn Monday, declared Khoury the winner by a 418-vote edge. He received 39,534 votes against Gemayel’s 39,116. Turnout was 46 percent.

The pro-government coalition retained its seat in the capital Beirut. Mohammed al-Amin Itani, a candidate of parliament majority leader Saad Hariri’s Future Movement, won easily after the opposition did not officially sponsor a candidate.

Sabei, whose ministry organizes the balloting, declared Itani a winner with 22,988 votes. An opponent came a distant second with 3,556 votes. Turnout was about 19 percent.

Sunday’s elections were considered a key popularity test for Aoun and Gemayel. Both are Christians, and the interfaith balancing act enshrined in Lebanon’s constitution provides that the president must be a Maronite Christian. The current president must step down before Nov. 23.

Aoun has already said he would run for president.

Security was tight in the two electoral districts.

Late Sunday, both sides claimed victory and accused the other of forgery. Each had supporters celebrating in convoys on the streets in Beirut and Metn.

Witnesses and security officials said loyalists of Aoun and Gemayel faced off in a neighborhood east of Beirut late Sunday, even with scores of Lebanese army troops and riot police deployed to prevent trouble.

Antoine Nasrallah, a spokesman for Aoun, told Al-Jazeera that one supporter was wounded in the hand after being shot by Gemayel supporters near the town of Bikfaya in Metn. Security officials said one person was slightly injured but did not say from which camp.

“We have been informed of our victory,” Aoun said through his OTV station. He accused authorities, however, of seeking to cancel one of the ballot boxes in the district of Jdeideh east of Beirut and asked supporters to head there. Partisan clashes were also reported in Jdeideh later Sunday.

Gemayel earlier on Sunday refused to concede defeat.

“Congratulations for your victory,” he told supporters outside his house, to the backdrop of fireworks. He also called for calm. “We don’t want anyone to drag us into a confrontation that we don’t need.”

Gemayel alleged there was voter fraud in one voting station.

While pro-government politicians accuse the opposition of being agents for Iran and Syria, Hezbollah leaders and Aoun accuse the ruling majority of subservience to the United States.

Gemayel and the government have accused Damascus of being behind the assassination of his son and a number of other anti-Syrian politicians and public figures over the last two years. Syria has denied the allegations.

With Eido’s death, Prime Minister Fuad Saniora’s margin in parliament was whittled down to only four seats.

The elections could exacerbate the country’s deepening political crisis because Saniora’s Western-backed government called them without the required approval of President Emile Lahoud, who has blocked attempts to replace the lawmakers. Lahoud, an ally of the opposition, considers Saniora’s government to be illegitimate.

Gemayel and his wife, Joyce, began the day by visiting their son’s grave before heading to the polling station.

“We visited Pierre to … promise him that his blood will not be in vain,” Gemayel said.