Police have seized a revolver, two live bullets and a sword from the possession of the arrested persons.
"We are on the lookout of two other persons who were also involved in Wednesday's incident," said Tangi police inspector Sunil Mohanty claiming that the two absconding criminals have already been identified.
Mohanty said a team of policemen arrested Hussain Khan and his brother-in-law Ghana Khan from Bhagatpur area on Thursday morning after raiding their hideout. Both the accused are in their late 20's and had previous criminal antecedents.
According to reports, a labour union meeting was underway at Bhagatpur industrial area on Wednesday evening when four persons came in two motorcycles and hurled bombs at the meeting place disrupting the meeting and spreading panic among the labourers.
While no one was injured in the bombing incident, the union leaders started chasing the antisocial elements who escaped from the spot but not before firing two rounds in the air.
Police believe the motive behind Wednesday's bombing and firing incident was internal rivalry between the labour unions.