Security forces shot dead three hardcore United Liberation Front of Asom (ULFA) militants in an encounter near Namsai, along the Assam-Arunachal Pradesh boundary on Thursday.Defence sources said the encounter took place when the Army and police launched a joint anti-insurgency operation in the area to flush out militants.The slain militants have been identified as Ramen Gogoi, Kapil Bora and Bikash.Two AK-47 rifles, one pistol, a grenade launcher, a magazine, some live ammunition besides cash amount of 42,160 rupees and Myanmar Kyat worth one thousand have been recovered from the spot of encounter.