NEW DELHI, Nov. 18 (Xinhua) -- At least three people were killed and 10 others wounded Sunday in a blast inside a prayer hall of a religious sect in northern Indian state of Punjab, police said.

The blast took place when a congregation of the Nirankari, a spiritual organization, was inside prayer hall of the Nirankari Bhawan in Rajasansi village of Amritsar city.

"Three people were killed and 10 others wounded today in a blast inside prayer hall of a religious sect here," senior police official Surinder Pal Singh Parmar said.

Police said the injured were immediately removed to Guru Nanak Dev hospital and Ivy hospital in Amritsar for treatment.

Amritsar is known as the Sikh holy city in India. However, Nirankari is a different sect.

Police teams have rushed to the spot to probe the matter.

"Police have launched an investigation and are studying footage from CCTV cameras in the area, besides collecting samples of the blast," an official said.

Local media reports quoting eyewitnesses said two masked bike-borne men came outside the Nirankari Bhawan and threw a grenade on the congregation.