Police on Mexico's Caribbean coast arrested 13 activists during a demonstration by Maya Indians against water rate hikes.

The Mayas were the original inhabitants of the area, south of the resort city of Cancun. But they have been pushed into poor, dry farmland inland as resorts pop up along the coast.

Households in Felipe Carrillo Puerto, the most important remaining Indian-majority town, had long paid a flat $5.20 monthly fee for water.

But the state water authority began installing water meters last year and started charging households more for water use of over 10 cubic meters (2,640 gallons) per month per family.

The Quintana Roo prosecutors' office said Thursday that activists took over the local water authority office Aug. 11 and held it for more than a week. It said state and local police forcibly removed the protesters Wednesday and arrested 13 activists. The water authority later said only nine were arrested and some of were not from Felipe Carrillo Puerto.

The activists were charged with rioting and abusing police. Those charges carry total maximum sentences of three years in prison.

The water authority said protesters attacked officers with stick and stones, but protest supporter Julio Lara Martinez of the leftist Democratic Revolution Party said police were too heavy-handed in their response.

"It is obvious that this is not a good mechanism on the part of the government, to use a heavy hand on issues that are very sensitive to people, like water," Lara Martinez said.

"The people of the Maya region have been shunted off to live in poverty, they haven't benefited from the big growth in the tourism sector," he said. "They are demanding some sort of agreement on a rate for an area that is totally depressed."

Miriam Chan, spokeswoman for the water authority, said that some farmers in outlying hamlets have negotiated low, flat water rates, but that the residents of Felipe Carrillo Puerto weren't eligible because they live in a larger town.

The Maya's ancestors built pyramids and temples across the Yucatan peninsula that were often abandoned by the time of the Spanish conquest. Their descendants still speak the language of their ancestors and survive largely by farming corn and tending fruit orchards.