Lt. Col. Samir Shehade, deputy chief of the intelligence department in Lebanon's national police force, was taken to the Hammoud hospital in Sidon, and hospital officials said his condition was stable.
The four dead were Shehade's aides and bodyguards, and another five were wounded in the attack, which occurred as Shehade's two-vehicle police convoy drove by the village of Rmaile, near the southern port city of Sidon.
Shehade's car, Tuesday (Photo: Reuters)
Interior Minister Ahmed Fatfat told the Lebanese Broadcasting Corporation that the blast was caused by a roadside bomb loaded with nails. He said it targeted the car normally driven by Shehade, who was traveling in the other vehicle at the time.
Fatfat did not say who might have been behind the attack but said it could have been aimed at Lebanese security forces, who are deploying to south Lebanon under a UN-brokered cease-fire deal that ended a month of fighting between Israel and Hizbullah guerrillas August 14.
Lebanese army troops are supposed to deploy in the south with a beefed-up UN peacekeeping force as Israeli troops withdraw.
Hariri's son: Attack a terrorist act
Shehade also was involved in the arrest last August of four pro-Syrian Lebanese generals in Lebanon. The four were arrested on suspicion of involvement in the February 2005 assassination of former Lebanese Prime Minister Rafik Hariri.
Security officials said Shehade was involved in the interrogation of several witnesses in the Hariri probe, including Syrian intelligence operative Husam Taher Husam.
The officials, speaking on condition of anonymity because of the sensitivity of the case, said Shehade had received threats because of his work in the Hariri probe.
Hariri's son, Saad Hariri, a prominent lawmaker in Lebanon, called the attack a terrorist act. "This is a message which we reject," he told reporters in Beirut.
The Tuesday explosion came 10 days before UN chief investigator Serge Brammertz was to submit a report to the UN Security Council updating his findings on the Hariri investigation.
Previous reports have implicated top Syrian and Lebanese security officials in the killing, which rocked Lebanese politics and led to the withdrawal of Syrian troops from Lebanon, ending a 29-year-military presence.
Syria denies any role in the Hariri slaying or the subsequent bombings.