Maoists-backed tribals and security forces on Monday exchanged fire at two places in restive Lalgarh where People's Committee Against Police Atrocities convenor Chhatradhar Mahato was to address a rally. Police and Central forces,in Lalgarh on an anti-Maoist mission since June 19,exchanged fire with Maoists at Palashidanga and Madhupur in West Midnapore district,close to Gohumidanga where Mahato was to address the rally,police said. The Maoists fled after the firing by security forces. Earlier,police demolished a stage set up for the tribal rally at the Gohumidanga High School with microphones being ripped off and taken away. A senior police officer said prohibitory orders under section 144 had been clamped to preempt the rally. Mahato,however,held a rally two km away from Gohumidanga where he announced an indefinite bandh from tomorrow in Lalgarh in protest against alleged atrocities on tribals by the security forces. Mahato,wanted by the police since the anti-Maoist operations began on June 19,said over phone,"If there is a warrant of arrest against me,why are they not arresting me? Why are they committing atrocities on tribals?" Mahato said the indefinite bandh would continue till the security forces leave Lalgarh and till the 23-point demands of the tribals are met. "We had planned to hold a peaceful rally. Why did the police impose section 144 and break up the stage at Gohumidanga? When other political parties are allowed to hold rallies,why are we not being allowed to do so in a democracy?" he asked. "In the name of anti-Maoist operations the security forces are committing atrocities on the tribal people." He alleged that the security forces opened fire on peaceful rallyists. Asked about firing from the side of tribals,he denied it saying,"from where will be get arms? Our movement is totally peaceful." West Midnapore SP Manoj Verma,however,said there was no firing by the security forces and no rally was held at Gohumidanga High School. "Chhatradhar does not have the means to hold a rally without the backing of Maoists," Verma said. Asked why he was not being arrested,Verma said,"He will be arrested when it is time."