Imphal/New Delhi: A powerful bomb exploded at the entrance of a festival ground on Wednesday killing one person in Manipur's East Imphal district ahead of Prime Minister Manmohan Singh's visit on Saturday.

Official sources said two women visitors were also injured while Union Home Minister P Chidambaram put the number of injured at four.

The explosion occurred when an unsuspecting rickshaw puller, who was paid Rs 20 to transport the bomb by militants, was placing it near the gate of the exhibition, official sources in Imphal said.

Chidambaram said the information he had was that the bomb was an Improvised Explosive Device(IED).

The site of the blast is about 50 metres away from the newly-constructed 'City Convention Centre' which is due to be inaugurated by the Prime Minister on December three.

The bomb exploded at around 11 AM at Hapta Kangjeibung ground where 'Sangai festival', in which many representatives from Thailand, Malaysia and other southeast Asian countries
were among the 400 delegates taking part, was being celebrated. The festival was concluding on Wednesday.

The rickshaw puller, identified as Kora, was killed, the sources said. The injured were taken to Regional Institute of Medical Science and hospital.

Chidambaram said that in the run up to the Prime Minister's visit Manipur remained on high alert.

"The information is IED was handed over to a person and before he could place it, it went off. He was severely injured. Four others have received minor injuries. The police have been able to speak to the person who is believed to have carried the IED and they have taken a statement," he told reporters in Delhi.

He said Government anticipated trouble in Manipur and very stringent measures have been taken. No individual or group has, however, claimed responsibility for the incident.

Official sources said the unsuspecting rickshaw puller was paid Rs 20 by militants believed to belong to the Kangleipak Communist Party (KCP) to place the bomb at the gate of the exhibition and it went off while he was drinking tea.

Thousands of people gather at the exhibition ground during the 'Sangai festival'. Sangai' is a rare brow-antlered deer found only in Manipur. Foreign representatives put up stalls to sell their wares.

The site of the blast is about 50 feet from the All India Radio(AIR) station in Imphal.

A faction of the KCP had called a 72-hour general strike in Manipur, which would end on Thursday at 6 AM, in protest against the prolonged economic blockade on national highways.