Gunmen abducted at least seven children in a suburb of Haiti's capital Port-au-Prince, the latest in a wave of kidnappings for ransom in the poor Caribbean nation, police said on Thursday (December 14). The children, all students at La Seve school in the Marin neighborhood, were kidnapped on Wednesday (December 13) when their school bus was hijacked on its way to school in the suburb of Marin. Bus driver John Cesar described what happened. "About 6:30 in the morning," he recalled, "three men were picking up garbage in the road. As I approached close to the garbage truck, I slowed down because I thought the truck was making a turn. When I stopped, three men pointed a gun at me and pulled me out of the car and drove away. This has to stop. The government must go if they can't do something about this situation." Police did not disclose the exact number nor the ages of the children but said they were in touch with the children's parents. The captors demanded an undisclosed ransom for the children, and U.N. and Haitian police were attempting to negotiate their release. Police have arrested three women-- including one believed to be the kidnapper's wife and another his sister-in-law-- who may be involved in the kidnappings. Residents joined police in a house-to-house search of the area and found one suspect who they killed and set on fire with gasoline. The rising number of kidnappings is threatening efforts to stabilize deeply impoverished Haiti two years after it's previous president was driven into exile in a violent rebellion. About 100 kidnappings for ransom were reported last month and at least 60 have occurred so far this month, including that of a 6-year-old boy in Port-au-Prince and murdered in the northern city of Cap Haitien. Haiti enjoyed a brief lull in violence after President Rene Preval won elections in February. But crime is rising.