For the second time in four days, a powerful bomb exploded close to Manipur Chief Minister Okram Ibobi Singh's official residence here this evening on the eve of Independence day.

There was no casualty, official sources said.

The bomb, an improvised explosive device, exploded at around 6:20 PM, 300 metre from the chief minister's official residence, in front of the City Convention Centre and near the state police headquarters, the sources said.

They said that the insurgents placed the IED on the footpath and possibly used a remote control device to explode it.

A police team led by DIG (Law and Order) Clay Khongsai blocked all exit routes and checked passers-by after the explosion, the sources said.

It was not immediately known how the insurgents infiltrated the high-security area and planted the bomb.

There were few people on the streets when the bomb went off in view of the boycott call of Independence Day celebrations by a coordination committee of six major insurgent organisations.

This evening's explosion followed a grenade blast in front of the chief minister's residence on August 10 for which militant outfit People's Revolutionary Party of Kangleipak-Progressive (PREPAK-P) had claimed responsibility.

The sources said police would investigate if there was any lacunae in security deployment as there was 24-hour patrolling in the capital complex.

Police have also been keeping vigil in non-VIP areas like Bamon Leikai, Mahabali, Keisampat, Imphal market complex, Uripok, Wangkhei surrounding the state capital.