The son of assassinated prime minister Rafik Hariri accused Lebanon’s new premier Monday of bowing to pressure from Hizbollah, which is refusing to turn over four members indicted by a UN-backed tribunal for the truck bombing that killed the Lebanese statesman in 2005. Prime Minister Najib Mikati fired back, suggesting Saad Hariri - himself a former prime minister - was trying to exploit his father’s death for political gain and tear apart the country. The implication of the Iranian-backed group Hizbollah in one of Lebanon’s most stunning crimes threatens to bring a new and violent crisis in this Arab nation on Israel’s northern border. The Shiite group denies any role in the killing and vows never to turn over any of its members. But the pro-Western bloc, led by Saad Hariri, said in a statement that Hizbollah is holding the country hostage by making it choose between justice and stability. Hizbollah - the dominant player in Lebanon’s new government - commands an arsenal that far outweighs that of the national army. “We will continue our struggle to end this supremacy of weapons,” Hariri’s group, known as March 14, said in a statement issued late Sunday. To that end, March 14 will “start working to topple this government” unless Mikati announces he will honour the tribunal in parliament this week. The March 14 coalition is named after a day of massive anti-Syrian protests in 2005. Immediately after Hariri’s assassination, suspicion fell on Hizbollah’s patron, neighbouring Syria. Mikati’s office’s reply to the March 14 ultimatum: Hariri’s bloc is launching a “campaign based on fabrications in order to mislead the public opinion and turn it against the new government”. The opposition figures, he said, “are taking advantage of the crime against martyr prime minister Rafik Hariri and his friends, to pour their anger and spite on the government”. The bombing that killed Rafik Hariri and 22 other people was one of the most dramatic political assassinations in the Middle East. A billionaire businessman, Hariri was Lebanon’s most prominent politician after the 15-year civil war ended in 1990. In the six years since his death, the investigation has sharpened the country’s dark history of sectarian divisions and violence. Rafik Hariri was one of Lebanon’s most powerful Sunni leaders; Hizbollah is a Shiite group. The investigation into Hariri’s death has renewed a long-standing debate over Hizbollah’s arsenal. Hizbollah was the only Lebanese faction allowed to keep its weapons under the agreement that ended the 1975-1990 civil war, on the grounds that it needed arms to fight any potential threat from Israel. Today, public sentiment on the weapons is mixed. Many Lebanese applaud Hizbollah’s ability to confront Israel, but critics accuse the group of running a state-within-a-state, using the threat of its weapons to get what it wants. Hizbollah leader Sheikh Hassan Nasrallah vowed Saturday never to turn over the four members of his group accused in Hariri’s killing, saying in a defiant speech that “even in 300 years” Lebanese authorities will not be able to touch them. He also promised the country would not see a new “civil war” linked to the findings of the UN-backed tribunal. But the assurance came with a tacit warning that peace in Lebanon depends on the government bowing to Hizbollah’s power and not pushing ahead with arrests. “There will be no civil war in Lebanon,” Nasrallah said. “This is because there is a responsible government in Lebanon that will not act with revenge.” Hizbollah has amassed unprecedented political clout in the government this year, having toppled the previous administration in January when Saad Hariri - who was prime minister at the time - refused to renounce the tribunal investigating his father’s death.