The militants opened fire under the cover of bamboo groves on SP A J Baruah and ADC Rajesh Prasad at Madhur Chowk in Barpeta last night when the two were returning from the house of a former BSF personnel Umesh Rabha who was killed by ULFA on Saturday, they said. No one was injured in the attack, police said.

Police personnel accompanying the district officials' vehicles opened retaliatory fire which continued for over half an hour. They ceased shooting on spotting women working in nearby fields.