A boat overloaded with an estimated 400 people struck a mooring post in an Amazon River port and flipped over, hurling passengers and crew into fast-moving water, a state oil company spokesman said.

Jorge Merino of Petroperu said 150 people were listed as missing after the boat Chachita ran into mechanical difficulties Monday, slammed into the wooden post and capsized before dawn on the Maranon River, which feeds into the Amazon.