They had earlier stated the toll in Piura province as 25, before correcting it to 24.
The bus, belonging to the Qorianka Tours company, departed from Lima and was en route to Tumbes, on the border with Ecuador, when it went off the road near the town of Organos, according to police.
Police at the scene told local media that the accident occurred at a difficult spot known as “Devil’s Curve,” but they said the cause remained under investigation.
An unknown number of injured passengers were transported to hospitals in El Alto and Mancora, popular resorts some 1,000 kilometers (620 miles) north of Lima.
Some passengers were from Haiti, the police said.
The number of Haitian migrants in Peru has been increasing, though the situation of those on the bus remains unclear.
Several passengers were thrown from the bus while others were trapped inside.
AFP