In a speech broadcast on TBC 1 public television, Magufuli said "it appears clear that the ferry was overloaded", adding that "negligence has cost us so many lives. children, mothers, students, old people".
Initial estimates showed that the MV Nyerere was carrying more than 300 people.
- By Friday morning, the machine recording the data and the ticketing officer's records had not been traced as search teams gave priority to finding survivors and bodies.
The rescuers were also retrieving bodies from the water. Local officials initially reported on Thursday that 100 people had been rescued.
Authorities were able to rescue 37 people after the passenger ferry MV Nyerere went down just meters from the dock on Thursday.
Mwanza police commander Jonathan Shanna said on Friday no foreigners had been found among the dead.
Company spokeswoman Theresia Mwami said exactly how many people were on board had not been established.
Tanzania's state radio reported passengers boarded the ferry at Bugolora, a town on Ukerewe Island, and was en route to the island of Ukara when it capsized.
Adam Malima, the Regional Commissioner. said: "We pray to God to give us hope in such an accident".
The ferry was said to have been particularly busy because it was market day in Bugorora, on Ukerewe island.
This will be the third major ferry disaster for Tanzania in recent years, after 500 people died on a Lake Victoria ferry in 1996 and almost 200 people died off the coast of Zanzibar in 2012.
Boat disasters are frequent on Tanzania's waters, where ferries often exceed their capacity. He recalled how crowded his trip on the aging ferry had been last month: "Most of us were standing up".
The deadliest such incident in recent decades was in May 1996, when about 800 people died after their ferry sank on the way to Mwanza in Tanzania.