More than 90 passengers were on the boat, leading officials to believe that the death toll will rise.
The boat overturned and sank at about 7 p.m. Saturday night, said senior police officer Zurah Ganyana. The owners of the boat did not have a license to operate and had overloaded the boat well past the point of being safe.
Lake Victoria is the largest lake in Africa and the third largest, by area, in the world after Lake Superior and the Caspian Sea.
The trouble began about midway through the cruise, not far from shore.
The vessel was believed to be overcrowded with almost 100 passengers, said Zurah Ganyana, a senior police officer at the scene. Inebriated partygoers suddenly found themselves flailing in the water, facing a life-or-death scenario.
"I send condolences to the families of the people who died in the accident on Lake Victoria last evening", he said.
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"Our rescue team is still on the ground trying to rescue whoever we can find", said Onyango. In September, more than 200 people died when an overloaded ferry sank on the Tanzanian side of the lake. Rescue boats were reportedly dispatched but turned back after seeing that the ferry was continuing with its voyage after passengers insisted on first getting to their destination. At least 27 people were rescued overnight, lower than earlier reports, she said. They sat under trees, looking through the wire fence and every time a body was pulled out of the water, there were screams and cries as some people recognised their loved ones. Others pored over sweaters, wallets, keys and shoes hoping to identify the dead.
He also revealed that the boat was unlicensed and unregistered.
There was a party going on aboard the boat, with loud music, at the time of the accident, Museveni said.
He advised the public to take lessons from Saturday's tragedy, regarding safety.
According to latest Update from Police Social Media Pages.
At least 29 people were confirmed dead after the accident, while 26 others had been rescued, President Yoweri Museveni said on his Twitter feed, adding that the operators of the boat would be charged with criminal negligence and manslaughter.