At least 100 people are known to have died after a ferry carrying hundreds of people capsized on Lake Victoria, Tanzania, officials say.
Many more are missing and it is feared that more than 200 people may have drowned. Rescue efforts resumed on Friday after being halted overnight.
The MV Nyerere ferry overturned near Ukara island on its way from Bugorora.
It is thought the overloaded vessel tipped over when crowds on board moved to one side as it docked.
Local media say the ferry's official capacity was 100 people but officials say the vessel was carrying more than 400 passengers when it capsized.
The BBC's Aboubakar Famau in Tanzania says fear has gripped residents of Mwanza region as they await to hear the fate of relatives who travelled on the MV Nyerere on Thursday.
"I received a call telling me that I have lost my aunt, father and my younger brother," says Editha Josephat Magesa, a local resident.
"We are really saddened and urge the government to provide a new ferry because the old one was small and the population is big."
Our reporter says the ferry's engines were recently replaced after local MP Joseph Mkundi complained about the previous ones.
Passenger figures unclear
Tanzania's police chief Simon Sirro Mwanza, who has travelled to the area, says the death toll has risen to 100.
So far, 40 people have been rescued and are in critical condition, according to Mwanza Regional Commissioner John Mongella. Local officials had initially reported on Thursday that 100 people had been rescued.
Exact figures, though, are yet to be confirmed - Reuters said the person who dispensed tickets for the journey also died, with the machine recording the data lost.
The ferry was said to have been particularly busy because it was market day in Bugorora.
The islands are close to Tanzania's second-largest city of Mwanza.
Tanzania has seen a number of nautical disasters, with overcrowding often playing a role.
In 2012, at least 145 people died when a packed ferry sank while transporting people to the island of Zanzibar in the Indian Ocean.
The year before, almost 200 people died in another major incident off the coast of Zanzibar. Hundreds survived, some found clinging to mattresses and fridges.
In 1996, more than 800 people died when the MV Bukoba capsized on Lake Victoria. It was one of the the worst ferry disasters of the last century.