Guwahati, Apr 8 (IANS): Assam remained largely peaceful on the 33rd raising day Saturday of the United Liberation Front of Asom (ULFA), despite threats from the anti-talk faction of the banned outfit led by its commander-in-chief Paresh Baruah alias Paresh Asom.

There were, however, three incidents -- two of them minor in nature -- in different parts of the state.

Late Saturday evening, ULFA claimed to have triggered a blast inside the Numaligarh Refinery Limited (NRL) in Upper Assam's Golaghat district leading to a major fire in the hydro-cracker unit of the refinery.

NRL's Manager (Corporate Communication) Madhuchanda Adhikari, however, said they were yet to ascertain whether the fire took place due to any blast or some technical problem.

"There was a fire at the hydro cracker unit of the refinery around 6.45 p.m. Saturday. We are yet to ascertain whether there was any blast, which led to the fire or it occurred due to some technical problems," she said while adding that efforts were on to douse the fire.

In other incidents, Assam police arrested four people from Lower Assam's Nalbari district on charges of sheltering ULFA militants and recovered one live round of .9 mm pistol and some incriminating documents including extortion notes from their possession.

Besides, forces of the Sashastra Seema Bal (SSB), which guards the Indo-Bhutan border in Assam, recovered a crude bomb from a remote location in lower Assam's Baksa district.