Jakarta – Police here said on Monday they had arrested at least 53 people suspected of involvement in a recent violent protest against the closure of illegal mines in Bangka Belitung province.

Forty nine of the suspects were accused of attacking the provincial governor's office during the Oct 5. protest against the closure of an illegal lead mine and three lead smelter companies.

The remaining four were arrested for illegal mining in Bangka Belitung, which caused huge state losses and environmental damage, the police said.

"We are examining the suspects. We are doing our best to follow any steps necessary so justice can be upheld," National Police spokesman Sr. Comr. Bambang Kuncoko said in Jakarta.

The Bangka Belitung Environmental Impact Control said that about 6,000 pit mining holes had been found across the province.

Unchecked and unregulated mining activities can lead to land degradation and increase the risk of flash floods and landslides in the rainy season and drought in the dry season.