CHENNAI, Oct 13 (Reuters) - Indian activists and politicians in the southwestern state of Goa, known globally for its pristine coastline and dense forests, are opposing a plan by Prime Minister Narendra Modi's government to turn Goa into a coal transportation hub.

Locals and activists have been protesting against three infrastructure projects - the expansion of a highway, railway and a power transmission network, according to local media reports, saying they cut through ecologically sensitive areas.

"The double tracking of railways, national highway 17B & 4A 4-laning, ... is only for coal, thus destroying our villages, displacing local communities," Goencho Ekvott, an umbrella organization of about two dozen rights groups, said in a petition to the Goa's Chief Minister Pramod Sawant on Tuesday.

India wants to increase coking coal handling at the state-run port in Goa, which could be transported to steel companies north of the state.

Activists say the projects are also likely to lead to the felling of thousands of trees in ecologically sensitive areas that are home to wildlife and bodies of water.

Alina Saldanha, a state assembly member from Modi's Bharatiya Janata Party (BJP), wrote to the federal environment minister last week, saying she had "serious concerns" over environmental clearances given to some projects.

Saldanha said the railway track expansion project would affect thousands of people, "destroy the environment" and "make it impossible to live" due to "noise pollution and coal dust pollution, making people prisoners in their own land."

"There are very many people who are completely opposed to these projects and their voices have not been represented," Saldanha said in a letter dated Oct. 7 reviewed by Reuters.

Nilesh Cabral, Goa's electricity minister from the ruling BJP-led coalition, said a majority of people in Goa supported the project.

"I am not for coal, but I am for development for the nation," Cabral told Reuters. (Reporting by Sudarshan Varadhan; Editing by Mark Potter)