Indonesian police carrying out an environmental crackdown in the main tin producing region of Bangka island, should stop targeting small-scale miners as it is hindering domestic smelters' supplies, the Indonesian Tin Industry Association said.

Small-scale traditional tin miners in Indonesia, the world's top tin exporter, have slowed mining activity because they fear being raided by the police, who have been intensifying a crackdown on illegal miners for the past few months.

Small smelters in the island off Sumatra depend on traditional miners for between 70 and 80 percent of their ore supply.

"The police come and get the miners," said Johan Murod, general secretary at the association and director of Bangka-Belitung Timah Sejahtera, which groups five private tin smelters on Bangka island.

"It is because government regulation is not helping with the mining situation in Bangka island," he told Reuters this week.

The government brought in a new mining law in 2009 that restricts the operation of small-scale miners, who tend to operate in an undisciplined way, causing damage to the environment, and do not pay royalties. A crackdown on illegal mining, tighter export regulations, declining onshore reserves and rain that had hindered production in Indonesia have helped drive the tin rally earlier this year.

"The government is not supporting the people for mining, they only support big companies," Murod added. "All mining causes environmental damage but after the mining, we (too) can make environmental improvements with the right regulation."

Bangka police follow up every complaint or report on illegal tin mining, which are made daily, and are committed to taking action against every mining violation, a spokesman said on Thursday.

Illegal small-scale miners who are caught by the police, are often not prosecuted, but instead shown mining areas that permit public mining, Bangka Belitung police spokesman Djoko Poernomo told Reuters.

"The police will continue to order prohibited activities or illegal activities which are against the law," he added. "This is not a seasonal action... many mining activities are being done at forbidden areas such as protected forest."