CAIRO, Egypt — The leader of Lebanon’s parliamentary majority claimed yesterday that Syria was behind a plot to assassinate him and the Lebanese prime minister ahead of crucial presidential elections next month.

Saad Hariri did not elaborate on the plot but when asked about reports that Syrian officials were behind it, he said, “We have information about this, and it is correct.” “The assassination is not only of me but of Prime Minister Fuad Siniora also,” Mr. Hariri, whose father — a former Lebanese prime minister, Rafik Hariri — was assassinated in a 2005 Beirut truck bombing that was widely blamed on Syria. Saad Hariri spoke to reporters after a meeting with President Mubarak of Egypt in Cairo. Lebanon’s anti-Syrian groups, which dominate the government, claim Damascus is behind a two-year killing spree that has claimed the lives of several anti-Syrian politicians and public figures. The latest was the September 19 slaying of lawmaker Antoine Ghanem in a Beirut car bombing.

Syria has denied involvement in any of the killings. Rafik Hariri’s assassination provoked an outcry that forced Syrian troops to leave Lebanon after a 29-year presence. The U.S. State Department said it couldn’t confirm Saad Hariri’s claims.

“Without commenting on the specifics on those allegations, it’s clear that there is a pattern of threat, intimidation, and use of violence against those who are trying to further the process of political reform in Lebanon,” a State Department spokesman, Sean McCormack, said.