In a statement Thursday, the two groups said their protesters came under fire from snipers on rooftops.
Bitar's predecessor, Fadi Sawan, was also forced to suspend his probe before he was finally removed in February.
Last year in August, hundreds of tons of ammonium nitrate, a highly explosive material used in fertilizers, which was improperly stored in the port for years, exploded to destroy parts of Beirut.
The new government faces a mammoth task that few believe can be surmounted, including undertaking critically needed reforms.
Last month, judge Tarek Bitar confirmed charges filed by his predecessor against outgoing Prime Minister Hassan Diab and three former ministers.
Lebanon’s economic and financial crisis has unfolded since late 2019, spiraling out of control in this country of over 6 million.
While COVID-19 has killed 1.7 milion people, the Black Lives Matter movement leads to a major debate about race and the toppling of statues of figures linked to slavery or colonisation.