A Lebanese police officer involved in the investigation of a former prime minister's slaying was critically wounded Tuesday in southern Lebanon in an apparent assassination attempt , security officials said.

Lt. Col. Samir Shehade was critically injured when a bomb went off near his car in the village of Rmaile near the southern port city of Sidon. It was not clear whether the bomb was placed under or near his car, said the officials, who spoke on condition of anonymity because they were not authorized to speak to the press.

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Al-Arabiya TV station said Shehade had been involved in the arrest in August last year 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.

The Tuesday explosion that wounded Shehade came just days before the U.N. chief investigator in the Hariri assassination, Serge Brammertz, was to hand his third report in the case to the United Nations.

Lebanon has been rocked by a series of politically motivated assassinations and bombings since Hariri's slaying, which some in Lebanon blame on Syria. Syria denies the allegations.

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