A day after three people were killed and 20 others got injured in a grenade attack in Amritsar, Punjab Chief Minister Captain Amarinder Singh on Monday announced a reward of Rs 50 lakh for information leading to the arrest of the suspects.

Information regarding the suspects can be provided at police helpline (181) and the identity of the informers will be kept secret, said media advisor to the Punjab Chief Minister.

"NIA team visited the blast site late last night along with their investigators and explosive experts. Held discussions with Punjab DGP and DG Intelligence," the media advisor added.

The blast occurred when few hundred people were gathered in a religious congregation at the Nirankari Bhawan in Rajasansi village.

"Currently we are looking into the details. The senior authorities will decide whether NIA will investigate the case or the state police," said IG (Border) Surinder Pal Singh Parmar.

Parmar further clarified that the police have not released any sketch of the suspects yet.

"We have not issued any sketches for the time being. Give us some time, and then we will be able to speak further on the matter," he said.

The NIA team is currently at the Nirankari Satsang Bhawan for further investigation into the matter.

On Sunday, Captain Amarinder Singh had also announced a compensation of Rs 5 lakh for the kin of the deceased and free treatment for those injured in the blast.