Raipur, Aug 14 (IANS) An alert was sounded across Chhattisgarh Sunday and security strengthened as the outlawed Communist Party of India-Maoist (CPI-Maoist) threatened to disrupt Independence Day functions Monday, police said.

Security forces moved into the interiors of the restive Bastar region in the southern tip of the state.

"The forces have been put on maximum alert in all five districts of Bastar besides Raipur, Dhamtari and Rajnandgaon districts," a senior police officer told IANS.

Units of the Anti-Terrorism Squad (ATS) have been deployed in the urban areas including this state capital.

The venue of the main function here Monday - the police parade ground where Chief Minister Raman Singh will hoist the tricolour - has been handed over to the ATS.

The entry and exit points of Raipur city have been sealed.

Maoists have put up banners and distributed leaflets in the jungle areas of Bastar region asking the people to stay away from the Independence Day functions, reports said.

The lone passenger train between Jagdalpur, the headquarters of Bastar region, and Kirandul in iron ore-rich Dantewada district was cancelled Sunday and Monday by the East Coast Railway.

Bastar is made up of Dantewada, Bijapur, Narayanpur, Bastar and Kanker districts.