The Cabinet took the decision on Wednesday, Reuters reported, citing ministerial sources.
The army will oversee the arrestees until responsibility is determined for the Tuesday explosion, the biggest to ever hit Beirut, in which the country’s main grain silo was destroyed.
The blast has so far claimed at least 113 and wounded 4,000 others, said Health Minister Hamad Hassan.
The powerful explosion that was felt as far away as Cyprus, leveled whole sections of the city, turning successive apartment blocks into masses of debris and twisted metal.
Some 300,000 people have also been displaced from their homes.
The Cabinet also announced a two-week-long state of emergency in Beirut, and asked security forces to ensure no one tampered with blast scene.
The country has pledged a transparent investigation into the incident.
Although, nothing has officially been determined, some media outlets alleged that officials “knew” about the dangers that are posed by storing ammonium nitrate — that is used in agriculture as a high-nitrogen fertilizer — but failed to do anything about it.
With destruction of the silo, the nation is now left with less-than-a-month’s supply of grain, but enough flour to avoid a crisis, the government says.
Also on Wednesday, the United Nations expressed serious concern about the fact that the explosion had come to compound the country’s multi-tier share of crisis.
“The UN generally, and UNRWA in particular, are very worried about the situation in Lebanon because of the many layers of this crisis. It’s an economic crisis, a financial crisis, a political crisis, a health crisis, and now this horrible explosion,” said Tamara al-Rifai, a spokeswoman for UNRWA, the UN agency that provides assistance to Palestinian refugees in Lebanon and other Middle East countries.
The Lebanese resistance movement Hezbollah has called for unity to overcome what it described as “national tragedy” following the deadly blast.