(CNN) — At least 127 people died when a ferry capsized Thursday on Lake Victoria in Tanzania, a government official told CNN.
Tanzanian President John Magufuli ordered the arrest of the operators handling the ferry, MV Nyerere, the state-run Tanzania Broadcasting Corp. reported Friday, citing Ambassador John Kijazi.
Magufuli declared three days of national mourning, starting Saturday, the Tanzania Broadcasting report added.
Kijazi confirmed the latest death toll in the report.
Transport Minister Isack Kamwele said 40 survivors were rescued Friday and 40 others were saved Thursday in the accident.
Rescue teams continued to search for hundreds who were likely onboard the overcrowded ferry.
Poor visibility halted rescue operations Thursday, but rescue efforts continued Friday.
“It’s been a bit difficult because of the fact that the ferry overturned with people and luggage,” Kamwele said. “We have to remove the luggage first to get to the bodies.”
Images from the scene showed rescuers in boats alongside the overturned ferry, picking up survivors in orange life rings. The rescuers were also retrieving dozens of bodies from the water.
The total number of passengers hasn’t been confirmed, but 400 people were estimated to have been on the overloaded boat, which had a capacity to carry only 100.
The ferry was traveling from Bugolora to Ukara Island when it capsized 200 meters (about 650 feet) from its destination. Thursday is a market day on the island, and many passengers were traveling to Gulio market there.
Lake Victoria is the largest lake in Africa, straddling the borders of Tanzania, Uganda and Kenya.
Ferries in Tanzania are often overcrowded, and the lack of an accurate passenger manifest is complicating rescue operations.
The disaster underlines the issue of dangerous overcrowding on ferries in the region.
In 2011, some 200 people were killed after an overloaded vessel — carrying more than 1,000 passengers despite an official capacity of 620 — hit strong winds off the island of Zanzibar in the Indian Ocean.