Guwahati, Nov 26 (IANS): Insurgent outfit ULFA had planned to carry out serial blasts and other subversive activities here ahead of Prime Minister Narendra Modi's scheduled visit to Assam, police said Wednesday.

Senior Superintendent of Police (City) A.P. Tiwary said two militants from the anti-talk faction of the United Liberation Front of Asom (ULFA) were targeting city buses in Guwahati.

"We have received information that two tribal boys, likely from the ULFA, are planning to keep explosives in city buses in Guwahati. Operations are on to nab them and an alert has been sounded," Tiwary said, and asked people for their cooperation.

Modi and Home Minister Rajnath Singh are scheduled to arrive Nov 29. Rajnath Singh will inaugurate the all-India conference of directors general of police at the Assam Administrative Staff College the same day.

Modi will address the conference Nov 30. He will also visit Nagaland, Manipur and Tripura before leaving for Delhi Dec 1.

Police have requested people to inform them if they get any information about the two youth or if they find anything suspicious.

Meanwhile, security has been tightened across the state ahead of Modi's visit, particularly after the recent blast in Dibrugarh district that left two people dead and close to 30 injured.

Police and the National Investigation Agency (NIA) said a bomb found in a train at Kendukona railway station was being carried to Guwahati to be exploded during the conference.