Updated

TEHRAN, Iran  -- Lebanese Prime Minister Saad Hariri was heading to Tehran on Saturday to seek Iranian support for his efforts to keep Lebanon stable amid tensions over a U.N. probe into the assassination of his father, Rafik Hariri.

The visit follows President Mahmoud Ahmadinejad's October tour of Lebanon, during which the Iranian leader reinforced Tehran's ties to the Lebanese militant Hezbollah group, a longtime protege of the Shiite powerhouse.

The exuberant welcome the Shiite Hezbollah staged for Ahmadinejad in Lebanon threw Hariri's Western-backed factions in the government on the defensive.

Lebanon's fragile unity government, which includes Hezbollah, has been struggling ahead of expected indictments by the U.N. tribunal investigating former Prime Minister Rafik Hariri's 2005 slaying.

Speculation that Hezbollah members will be indicted in the case has fueled fears of a new political crisis and violence in Lebanon, and raised concerns over what Iran's would do in that case.

In remarks in English, released by his office ahead of the Iran visit, Hariri underlined concerns for stability.

"Impairing the stability of any country of the region is a threat to the interests of Arabs and Iran at the same time," Hariri said. "Therefore, I consider that Iran is concerned by all effort to provide elements of stability in all countries of the region, including Lebanon."

Hariri is expected to meet Iran's Supreme Leader Ayatollah Ali Khamenei and Ahmadinejad during the two-day visit, as well as other top Iranian officials, Iranian state television reported.