"Those who assassinated Mohammad Shateh are the ones who assassinated Rafik Hariri; they are the ones who want to assassinate Lebanon," Hariri said in a statement.
"The suspects are those who are running away from international justice and refuse to appear in the Special Tribunal for Lebanon; they are the ones opening the window of evil and chaos to Lebanon and the Lebanese and are drawing regional fires,” he added.
Six people were killed and 70 others injured as a blast struck central Beirut as Shateh's convoy was passing.
Hariri said that Friday's bombing as "the latest terrorist message to us; we, in the Future Movement and the March 14 coalition, are the free Lebanese”.
TV footage showed fires and human remains following the powerful explosion.
According to Future television, the blast was caused by a booby-trapped car.
No group has claimed responsibility for the bombing.
Shateh's killing in the blast came shortly after the former minister tweeted criticism of Hezbollah over its involvement in the Syrian conflict.
Last month, at least 24 people were killed and scores injured when a deadly blast targeted the Iranian embassy in Beirut.
In August, at least 83 people were killed in two blasts in southern Beirut.
englishnews@aa.com.tr
