KAMPALA, Uganda (AP) — At least 44 people are dead after a passenger ferry capsized on Lake Victoria, a Tanzanian official said late Thursday, and the death toll was expected to rise when rescue efforts resume at daybreak.

Thirty-seven people were rescued after the ferry sank in the afternoon, Mwanza regional commissioner John Mongella told The Associated Press.

"I cannot speculate" how many people had been on board, he said. "Right now our focus is on rescue."

Such ferries often carry hundreds of people and are overcrowded.

The Tanzania Electrical, Mechanical and Electronics Services Agency, in charge of servicing the vessels, urged patience in a statement as rescue efforts began.

The ferry had been traveling between the islands of Ukara and Bugolora and capsized near the area of Mwanza, it said.

Accidents are often reported on the large freshwater lake surrounded by Tanzania, Kenya and Uganda.

Some of the deadliest have occurred in Tanzania, where passenger boats are often said to be old and in poor condition.

In 1996 more than 800 people were killed when passenger and cargo ferry MV Bukoba sank on Lake Victoria.

And in 2011 nearly 200 people were killed when the MV Spice Islander I sank off Tanzania's Indian Ocean coast near Zanzibar.

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