NAIROBI - Tanzanian President John Magufuli on Friday ordered the arrest of the management of a ferry that capsized in Lake Victoria, as the death toll climbed to 136 and rescue workers pressed on with the search to find scores more people feared drowned.

The country's Electrical, Mechanical and Services Agency said it is unknown exactly how many passengers were aboard the MV Nyerere when it sank on Thursday near Ukara Island, in the southeast of the vast lake, which also extends into Uganda and Kenya.

The ageing ferry, whose hull and propellers were all that remained visible after it overturned, was also carrying cargo, including sacks of maize, bananas and cement, when it capsized around 50 meters from Ukara dock.

Initial estimates suggested it was carrying over 300 people - more than double the ferry's capacity - when it overturned.

"It's feared that a significant number (of people) have lost their lives," said George Nyamaha, head of Ukerewe district, which includes the island.

The death toll rose to more than 136 on Friday, the police said.

John Mongella, governor of the Mwanza region, said early on Friday that 37 people had been rescued, though some survivors were in "a very bad condition".

He refused to speculate on how many were aboard the vessel, saying only that "right now, our focus is on rescue".

No foreigners have been found among the dead, Mwanza's police commander, Jonathan Shanna, said on Friday.

"I have not heard from either my father or my younger brother who were on the ferry. They had gone to the market in Bugolora to buy a school uniform and other supplies for the new school term," said Domina Maua, who was among those seeking information about loved ones.

Davita Ngenda, an elderly woman, had already received bad news. "My son is among the bodies recovered," she said, weeping. "He had gone with his wife but she has not been found yet. My God, what did I do to deserve this?"

With a surface area of 70,000 square kilometers, oval-shaped Lake Victoria is roughly the size of Ireland. Capsizes are not uncommon, and the number of fatalities is often high due to a shortage of life jackets and the fact many people in the region cannot swim.

The deadliest accident in recent decades was in May 1996, when around 800 people died after their ferry sank on its way to Mwanza in Tanzania.

Waters in the lake can be rough, and boats are frequently poorly maintained, while ferry operators often fail to record the number of passengers on board.

In March 2012, only two survivors were found after a boat believed to be carrying 60 people capsized on the lake in Uganda.

Lake Victoria is the source of the White Nile, one of the main two tributaries of the Nile River, which stretches north nearly 6,700 km into Sudan and Egypt.

AFP - AP - Reuters - CGTN