The three HPC (D) cadre, suspected to be involved in violent activities, were netted in Cachar last night and brought to Aizawl, a senior police officer said.
He said that one of the arrested militants - Reuben Lalromawia (19) of Saipum village at Assam border - was suspected to be among the HPC (D) group which ambushed members of the state assembly committee on government assurances near Manipur border's Zokhawthiang hamlet on March 28 last in which three policemen were gunned down.
The three legislators - Chairman of the committee and other two legislators were unharmed in the ambush.
Another militant, 'Sergeant' Lalchuailova (36) alias L C Hmar was also allegedly involved in the attack on the police outpost at the Manipur border's Khawlian village on March 5 last.
The third cadre, H Lala (68) from Assam border's Vairengte town, was suspected to be involved in luring and recruiting young Hmars to join the militant outfit, the officer said.