The forest mafia which was operating during the time of A.K. Antony and K. Sudhakaran is becoming stronger under Oommen Chandy and K.P. Viswanathan, Opposition leader V.S. Achuthanandan said in Jeerakarappara in Kerala. Talking to mediapersons after visiting Jeerakappara, where illegal tree felling was reported, he said the mafia cleverly used the uncertainty that prevailed during the transition period between the two ministries to carry out their operations.