A powerful improvised explosive device (IED), weighing about two and half kgs, was seized along the roadside of Imphal-Jiribam-Silchar national highway (NH) in Manipur’s Imphal west district, police said on Wednesday.

They said a road opening party (ROP), 18th Sikh Regiment personnel, detected some suspicious object at Konthoujam area on Tuesday which later turned out to be a powerful bomb.

The bomb was allegedly planted by insurgents to attack security and police personnel, sources said adding that it was later detonated at a safe place.

Official sources said security measures have been tightened particularly in four valley districts of Imphal east, Imphal west, Bishenpur and Thoubal in view of frequent planting of powerful bombs at roadsides to attack the security personnel.

Meanwhile, four insurgents -- three of People’s Liberation Army (PLA) and one of People’s Revolutionary Party of Kangleipak (progressive), PREPAK-P, were arrested during various search operations at Uripok, Paona Bazar and other areas here last evening, sources said.

Sources identified the four as Kharibam Robi (41), Yumlembam Jokumar (32), Ngangbam Rishikesh (22), all PLA insurgents, and Telem Boy (40), PREPAK-P, adding that one 9mm pistol and some other material were recovered from them.

Sources said security patrol has also been intensified at various places in view of the 35th year foundation day today of the Revolutionary People’s Front (RPF), political wing of the PLA.

Frisking of passers-by was being carried out at many places to detect movement of the insurgents, sources said.