Bombs ripped through two buses in a Christian area of Lebanon on Tuesday, killing at least three people.
The blasts came as the deeply divided nation prepared to commemorate former prime minister Rafik Hariri's assassination two years ago.
At least 20 people were wounded in the co-ordinated attack, the state-run news agency said.
The attack occurred shortly after 9 a.m. on a road in the village of Ein Alaq, just south of the mainly Christian town of Bikfaya in the hills northeast of Beirut.
A security official, speaking on condition of anonymity because he was not authorized to talk to media, said the blasts were minutes apart.
As people scrambled to the scene of the first blast, a second explosion tore through a bus that had been following behind, the official said.
The death toll was initially reported as much higher. But the lower toll of three dead brought the count in line with that of the Red Cross.
Security officials estimated the "banana-shaped" bombs weighed between four and seven pounds. They were packed with metal pellets and placed under seats, officials said.
The Voice Of Lebanon radio station said the targeted buses had been transporting people to work.
Ein Alaq is near Bikfaya, the ancestral home of the Gemayel family, one of the most prominent political Christian families in Lebanese politics.
Cabinet member Pierre Gemayel, a leading anti-Syrian politician, was assassinated in November. His father, former President Amin Gemayel, visited the White House and met with Bush last week.
The bombings come a day before supporters of the U.S.-backed government were to mark the anniversary of Hariri's 2005 assassination with a huge rally in Beirut.
Walid Jumblatt, a senior pro-government politician, speculated that the blasts were meant to scare people from congregating at the rally to commemorate Hariri, the subject of a UN probe that has pointed the finger of blame at Syria.
"It's to terrorize people who are willing to come," Jumblatt told Al-Jazeera television.
Organizers of the rally in downtown Beirut said there were no plans to cancel it.
Senior government, military and security officials were set to meet later in the day to discuss how to keep Wednesday's rally from turning violent.
Sectarian tensions have been running high in the deeply divided country.
Lebanon has witnessed 15 attacks on politicians, journalists and public places since Hariri's slaying on February 14, 2005.
Many Lebanese blame the attacks on Syria, which has always denied accusations of involvement. Syria has so far not responded to Tuesday's events.
"Syria has always denied accusations of involvement but this is coming on the eve of a planned major demonstration in the heart of Beirut tomorrow for the anniversary of the killing of Hariri will certainly reinforce fears of many people in Lebanon that there are still those who are trying very much to stir up civil strife," Middle East correspondent Jerrold Kessel reported on Â鶹´«Ã½net from Jerusalem.
"The whole country has been unsettled since last year's war between Israel and Hezbollah and the reconstruction efforts in the aftermath of that war and the attempts by Hezbollah to gain a stronger political foothold in the country."
Lebanon has been locked for months in a power struggle with Hezbollah-led opposition.
The crisis gained momentum when six ministers from Hezbollah and its pro-Syrian allies left their government posts in November mainly over the cabinet's endorsement of a UN tribunal for Hariri's murder.
Tensions erupted in street clashes between supporters and opponents of the Western-backed government after the opposition called for a one-day protest strike. Seven people were killed in the fighting.
"It is these pro-government troops that have been planning that memorial in Martyr Square in the heart of Beirut tomorrow to mark Hariri's assassination, despite the concern that there might be friction with opposition supporters backed by Hezbollah who have been camped out for more than two months in that square as part of a campaign to topple the anti-Syrian government," Kessel said.
The anniversary of Hariri's assassination also falls six months to the day that a UN-brokered ceasefire brought an end to a war between Israel and Hezbollah. The summer war lasted for 34 days and left more than 1,000 people dead, with heavy casualties on both sides.
With files from The Associated Press
