An ULFA (I) militant was killed in a police encounter and huge cache of explosives was recovered in two separate incidents, ahead of Prime Minister Narendra Modi's two-day visit to Assam from November 29.

Acting on a tip-off, police recovered four rocket launchers, a carbine, 40 live cartridges and five explosives from a field in Gorsinga No 2 Tokajan village of Tinsukia district this morning, Additional Superintendent of Police Sauravjyoti Saikia said.

In another major haul, three cartons containing 30 packets of gelatin sticks, 1,800 packets of detonators and 12 packets of cordex wire hidden inside gunny bags were recovered during routine checking of vehicles on the Gauahati-Shillong Road in Dispur police station area in the early hours.

The vehicle was coming from Meghalaya and its driver and the lone passenger were detained, Guwahati City Senior Superintendent of Police A P Tiwari said.

Meanwhile, an ULFA(I) cadre was killed in an encounter with police while three others managed to escape at Betonisuk in Dibrugarh district, police said.

ULFA(I) militants struck back killing an employee of a petrol pump and critically injuring two others at Khelmati in North Lakhimpur district, Superintendent of Police P K Bhuyan said.

Search operations have been intensified following intelligence inputs on Wednesday that two youths, possibly belonging to the ULFA (Independent), were planning to keep explosives in city buses and that ULFA(I) may indulge in violence ahead of the prime minister's visit, police officials said.