Around 15 people were injured in the blast, Xinhua reported. Shatah was killed when a car filled with explosives went off near his convoy in the city's Starco complex.
He was on his way to former prime minister Saad Hariri's residence to attend a meeting for an opposition conclave early next year.
Around 15 people were injured in the blast, Xinhua reported
Shatah had served as adviser to former prime minister Fouad Saniora and his successor Hariri. Early estimates said around 30 kg of highly combustible elements were used in the blast.
Earlier reports suggested that at least 12 people were killed. Beirut has been hit by several deadly attacks over the past months, including twin suicide bombings in November that targeted the Iranian embassy.