Three weeks after Jharkhand Chief Minister Babulal Marandi announced his government’s decision to set up a Special Task Force (STF) to check Naxal violence, the STF has failed to take off. And yesterday’s incidents, in which six CRPF jawans were killed when MCC activists ambushed a patrol party and a police convoy in Latehar district, would serve to be a grim reminder of the fact that the state government has not been serious enough in its efforts to crack down on Naxal activities.Marandi had announced last month to set up an STF after 19 cops were ambushed by Naxals in West Singhbhum district on December 19.Asked about the STF, Jharkhand IG (Operation) R.C. Kaithal, who had been appointed chief of the STF, said: ‘‘I don’t know what this STF is all about.’’ And DGP R.R. Prasad’s reply to the same query was: ‘‘The STF was not set up because we lack forces.’’It was around 11 am yesterday when a patrol party was ambushed by MCC ultras near the Chandawa Police Station in Latehar, leaving one CRPF constable dead and six Jharkhand police personnel injured.In another incident that happened near the Amjharia valley on the Ranchi-Palamau Road at around 5 pm, a convoy of four police vehicles were attacked by the ultras. Five CRPF jawans died in the attack.‘‘We are trained to fight till death. But the extremists don’t fight. They kill people in ambush,’’ said a CRPF constable.Official sources said that three days ago, the state Intelligence Department had provided specific details about possible MCC attacks in Latehar, Lohardaga and Palamau to the SPs of these districts.