Updated

At least 29 people have been killed by floods and mudslides in northern Brazil as authorities struggle to rush aid to dozens of small cities cut off from civilization by overflowing rivers in the Amazon region, officials said Wednesday.

Months of heavy rains extending from the Amazon jungle to the Atlantic coast have dislodged nearly 200,000 people from their homes and stranded thousands more in 10 states, according to civil defense officials.

Local news media reported that three other people were killed, but authorities did not confirm the deaths.

At least eight people died in the Amazon region of Maranhao state, the most affected area so far. Maranhao civil defense official Abner Ferreira said authorities were struggling to aid those affected because at least six highways were shut down due to the rains.

"We are having difficulties getting help to people because many roads have been swept away with the floods," Ferreira said. "We have two helicopters from the air force. We are using trucks and boats to get people help."

Television footage showed the rooftops of houses poking out of water in flooded towns and people using boats to move around in their cities.

The rains also prompted the temporary closure of a railway that takes iron ore from the sprawling Carajas mine in the neighboring jungle state of Para, according to a statement from miner Companhia Vale do Rio Doce SA.

Iron ore, the main ingredient in steel, is shipped overseas from Sao Luis, the state capital of Maranhao. The railway also transports 1,300 people per day. Vale is the world's second- largest mining company and the planet's biggest iron ore producer.

Brazilian President Luiz Inacio Lula da Silva flew over the hardest-hit areas on Tuesday, delivering food baskets to shelters and meeting with local officials. Silva promised aid to repair infrastructure, while voicing concerns that global climate change could be responsible for the unusually heavy rains and destruction.

Floods and mudslides late last year in the southern state of Santa Catarina killed more than 100 people, displaced 80,000 and set off a round of brutal looting in a devastated port city by people desperate for drinking water and food.

More rain is expected in the north in coming weeks, officials said.