Rescuers throng a beach in Lake Victoria where a ferry with unknown number of passengers capsized. [Isaiah Gwengi/Standard]

A massive rescue operation is underway after a passenger ferry capsized on the Kenya side of Lake Victoria in Siaya County.

Authorities had not established the number of casualties by the time of going to press but it was feared that scores may have lost their lives in the Saturday evening accident.

The water bus has a capacity of at least 200 passengers and was sailing from Mageta Island to Usenge in Bondo Sub county.

Siaya Governor Cornell Rasanga and County Commissioner Joseph Ole Tialal confirmed the accident but could not confirm any casualties, saying details were still scanty. "We have launched investigations into this unfortunate accident," Mr Tialal said.

He said officers on the ground have reported that those who were on board were rescued by the rescue boats that were in the Lake.

They, however, could not confirm if everybody who was on board has been rescued. "They are currently interviewing those who have been rescued to get the correct numbers even as they await official confirmation from the water bus company on the number of people who were on board".

The county commissioner said the ferry which was half submerged in water could be seen being swept away by strong waves towards Uhanya beach.

Mr Rasanga told The Standard that water bus drifted and sank as it neared docking at Usenge. "There is no clear information on casualties but there are reports that all the passengers may have been rescued," said Rasanga.

He added: "There is ongoing investigations to ascertain the exact number of people who were on board."

According to Kenya Maritime Authority (KMA), there are about 40 water transport vessels accredited to transport passengers within the Kenyan waters of the lake. These include water buses, ferries and small boats known as choppers.

But the five ferries with a capacity of between 80 to 250 passengers, water buses carrying between 60 and 150 people, and choppers carrying between 20 to 40 only ply major routes which include; Mbita-Lwanda Kotieno, Mbita Mfangano, Usenge-Mageta, Mbita-Takawiri-Mfangano, Asembo Bay-Uyoma and Mageta Island.

The accredited vessels are however not enough to serve the over 100 routes with about 2, 000 beaches within the Kenyan waters, a situation which has seen hundreds of unauthorised operators venture into the business.

At least 50 other routes remain neglected, with travelers having to embrace the risky unaccredited boats which come it to fill the gap.