Rescue efforts continue as death toll hits 136 after boat suspected of carrying too many people capsized.

The death toll from Tanzania’s ferry disaster hit 136 on Friday as hopes faded for more people being pulled out alive from Lake Victoria.

Thirty-seven people were rescued after the MV Nyerere sank on Thursday near Ukerewe island on Africa’s largest lake.

“People are aware that the hopes of finding survivors are almost nil,” Tanzanian state television reported.

The cause of the accident was not immediately clear, but overloading is frequently to blame for such incidents.

The number of dead was expected to rise, according to witnesses.

“More than 200 people are feared dead,” based on accounts from fishermen and others nearby, because passengers had been returning from a busy market day, Tanzania Red Cross spokeswoman Godfrida Jola told The Associated Press.

“But no one knows” just how many people were on board, she said.

Rescue workers at the scene of the ferry disaster on Friday [Reuters]

President John Magufuli said he ordered the arrest of “all those involved in the management of the ferry”.

“It appears clear that the ferry was overloaded. The arrests have already begun,” he said in a speech on TBC One public television, also referring to “negligence”.

The ageing ferry’s hull and propellers were all that remained visible after it overturned.

Davita Ngenda, a victim’s relative, had already received bad news. “My son is among the bodies recovered,” she said, weeping.

While the boat had a capacity of 100, it remained unknown exactly how many people were on the vessel.

George Nyamaha, head of Ukerewe district council, said “more than a 100 passengers” were on board when the ferry sank. Local media, quoting witnesses, reported numbers as high as 400 to 500.

‘Stay calm’

Al Jazeera’s Catherine Soi, reporting from Nairobi in neighbouring Kenya, said the boat was also carrying cargo when it went down.

“People are saying that this ferry was just going to dock when people rushed towards one side of that ferry and that is what might have caused it to topple,” she said.

Magufuli was “deeply saddened” by the disaster and called on Tanzanians to “stay calm during these difficult times”, according to spokesman Gerson Msigwa.

The country’s opposition, however, accused the government of “negligence”.

“We have often raised concerns about the poor condition of this ferry, but the government turned a deaf ear. We have repeatedly denounced this negligence,” said John Mnyika, deputy secretary-general of Chadema, the main opposition party.

Mnyika said overloading was “another failure of the authorities” and criticised “inadequate relief efforts as well as delays” in the rescue operation.

With a surface area of 70,000 square kilometres, oval-shaped Lake Victoria is shared by Tanzania, Uganda and Kenya.

Accidents such as these are not uncommon on Lake Victoria and overloading is often to blame.

In 1996, a ferry disaster in the same region killed more than 500 people. In 2012, 145 people died in a ferry disaster in Tanzania‘s semi-autonomous archipelago of Zanzibar, in the Indian Ocean, on a vessel that was overcrowded.