Water pollution disasters in Mexico have turned into political battles as officials struggled Wednesday to blame each other for the problems.

A town in western Jalisco state is fighting state officials over what caused the death of more than 200 tons of fish at a local lake.

Jalisco state inspectors said Tuesday that the fish, a species of chub, were killed by high levels of sewage dumped into Lake Cajititlan. The head of the state forensics office, Marco Antonio Cuevas Contreras, said fecal coliform levels were six times higher than permissible limits.

"The death of the fish ... was caused by the lack of oxygen due to the high level of pollution in the lake," he said.

The city government of Tlajomulco, which borders the lake and is responsible for water treatment, called the report "false, irresponsible and inconsistent."

"We condemn the selective handling and politicization of this environmental issue," the city said in a statement. "We won't be a party to these low blows."

The city has re-opened the lake to boaters and has blamed everything from changes in temperature, algae blooms and accumulations of natural sediment for the death of hundreds of thousands of the finger-size fish.

Also on Wednesday, the governor of northern Sonora state angrily attacked federal environmental officials in a full-page newspaper ad and demanded they be expelled from his state.

Sonora, a dry border state, experienced one of the worst mining spills in recent memory when 10 million gallons (40,000 cubic meters) of copper sulfate and heavy metals leaked into two rivers, threatening water supplies for thousands of people.

Gov. Guillermo Padres blamed federal authorities for not doing enough to stop or remediate the Aug. 7 spill.

But the disaster was overshadowed this week when local media revealed that Padres had dammed a river that runs through a ranch owned by his family.

Federal officials, known as delegates, said the governor hadn't gotten permits to build the dam, drawing his ire.

"I do not consider these delegates as valid representatives of federal agencies, they are not welcome, and I call on their agencies to send other representatives," Padres said.

Water is a hot-button issue in Sonora, where a ranch like the one owned by Padres' family would be worth little without the dam. Padres has argued that a smaller dam already existed at the site and was merely expanded.