RIO DE JANEIRO — A boat carrying 70 people sank on a major river in northern Brazil leaving at least 10 dead and dozens missing, authorities said Wednesday.

The public security office of the state of Para said 15 people made it to the shore and 10 bodies were recovered, while the rest were unaccounted for. Earlier the office had reported that 25 reached the shore.

Authorities said the boat was traveling on the Xingu River when it sank late Tuesday. The cause was not immediately clear.

The Folha de S. Paulo newspaper said the vessel left Monday night from Santarem and was heading to Vitoria do Xingu.

Survivor Bruno Costa, a 29 year-old disc jockey, described a chaotic scene as the boat cracked apart and quickly sank. He told the G1 news portal that a tarpaulin sheltering passengers from a heavy downpour made it escape difficult.

“The tarp prevented many people from leaving. I managed to rescue a child of about 2, but neither I nor the child had a life jacket on,” Costa said.

Costa said a man trying to get off the boat suddenly jumped on his back and grabbed the child away from him. He last saw the man sinking in the river and did not know what happened to the child. He told G1 he found a life jacket and used it to stay afloat, but he saw many others in the water who “failed to make it.”

Travel by river is common in Brazil’s northern states, which include the Amazon rainforest and have relatively fewer major roads.

In early August a cargo vessel collided with a tugboat on the Amazon River, also in the state of Para. Only two people were rescued out of 11 aboard the tugboat.