Lebanon ? In a probable blow to the Western-backed government, a key opposition leader Sunday declared victory in voting for a seat in parliament that was widely regarded as a proxy fight between the government and the pro-Syrian opposition.

Under guard by soldiers, tens of thousands of voters cast ballots in mountain villages northeast of the capital, where two civil war veterans and former allies were pitted against each other in a heated struggle for the Christian vote.

After the opposition leader declared the victory, the faction aligned with the government immediately claimed fraud but urged its followers to remain calm.

Amin Gemayel, an ally of the Western-backed Sunni government, was competing in the election for the seat of his dead son against a relatively unknown candidate, Kamil Khoury, who was backed by Gen. Michel Aoun, an ally of the Shiite-dominated opposition.

Pierre Gemayel, a young, popular Cabinet minister, was shot and killed late last year. His supporters believe Syria had a hand in his assassination, a charge denied in Damascus.

Late Sunday evening, Aoun’s camp announced it had won the seat. But official results were not expected until today.