Speaking in a televised speech on Friday, Nasrallah said those responsible for the deadly disaster had to be held to account regardless of their affiliations.
He stressed that the probe should have neither political nor sectarian motives.
The powerful explosion on Tuesday took place at port warehouses storing highly explosive material, specifically ammonium nitrate, commonly used in both fertilizer and bombs, killing 154 people and injuring a whopping 5,000 others.
Describing the blast as a massive humanitarian and national catastrophe, the Hezbollah chief called on all the Lebanese to unite to overcome the ordeal.
He also dismissed as “injustice” media speculation in the early hours of the tragedy that Hezbollah had stored missiles in the port, adding that those accusations aimed to incite the Lebanese people against the resistance group.
Nasrallah rejected the claims, and said those media outlets that spread the allegations had had political motivations and sought to incite a civil war in Lebanon.
The Hezbollah chief also expressed the resistance group’s readiness to help all the victims of the explosion. “We are ready to shelter the homeless families and to provide them with alternative housing,” he said.
On Wednesday, Beirut’s Governor Marwan Aboud said the blast had left 300,000 people homeless.