At least 136 bodies have been retrieved from Lake Victoria in east Africa after a ferry sank on Thursday, Tanzanian officials have said.

Scores more were reported missing as rescuers searched for survivors.

The MV Nyerere, with a capacity to hold 101 people, had been dangerously overloaded, the government’s chief secretary John Kijazi told reporters. He ordered an investigation and said those responsible will face charges.

Initial estimates suggested that the ferry was carrying as many as 300 people when it capsized between Ukerewe, Lake Victoria’s largest island, and the smaller island of Ukara. The precise number was unknown, however, because the ticket-seller had drowned and the machine recording sales had not been found.

At least 37 people were brought to safety on Thursday, some in “a very bad condition”, said John Mongella, the commissioner for the Mwanza region in northern Tanzania. It was unclear whether any new survivors have been found since rescue operations resumed on Friday morning. Dozens of security forces and volunteers wearing gloves and face masks spent the day hauling bodies into wooden boats.

Facebook Twitter Pinterest Red Cross volunteers on Ukara Island in Lake Victoria. Photograph: AP

Tanzanian ferries often carry hundreds of passengers and are overcrowded, and there are shifts in weight as passengers move to disembark. The Nyerere was crowded because it was a market day.

Domina Maua, who was among those at the dockside seeking information about survivors, said: “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.”

Davita Ngenda, an elderly woman in Ukara, wept as she said. “My son is among the bodies recovered,. He had gone with his wife but she has not been found yet. My God, what did I do to deserve this?”

Sebastian John, a teacher, said such tragedies had become part of life for those who live near the lake. “Since my birth, people have gone to their deaths on this lake, but what are we to do? We did not choose to be born here, we have nowhere to go,” he said.

The ageing ferry, of which the hull and propellers were all that remained visible, was also carrying cargo, including sacks of maize, bananas and cement, when it capsized about 50 metres from Ukara dock. The cause of the accident was not immediately clear, but overloading is frequently to blame for such incidents.

President John Magufuli was “deeply saddened” by the disaster and urged Tanzanians to “stay calm during these difficult times”, according to a 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, the 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 sq km (27,000 sq miles), the oval-shaped Lake Victoria is roughly the size of Ireland and is shared by Tanzania, Uganda and Kenya. Capsizes are not uncommon and the number of deaths is often high owing to a shortage of lifejackets and the fact that many people in the region cannot swim.

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.

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

About 20 people were killed in December 2016 when a boat overturned on the lake as it was carrying passengers to mainland Uganda for the Christmas holidays. In March 2012, only two survivors were found after a boat carrying about 60 people capsized on the lake in Uganda.