A suspected bomb blast during a Christian prayer meeting in India's southern state of Kerala killed one person and wounded 36 others, police said Sunday.

"At about 9:40 a.m. approximately there was an explosion in Zamra International Convention Center in which one person died and 36 are undergoing treatment," Director General of Police of Kerala Darvesh Saheb told reporters.

"We will find out who is behind this and take stringent action… preliminary investigation shows it was an IED (improvised explosive device) blast."

More than 2,000 people were attending a three-day Jehovah's Witnesses prayer meeting at a convention center in Kalamassery near the port city of Kochi when the blast ripped through the crowd.

"We are examining all angles and will find out who is behind this," Saheb added.

The Press Trust of India news agency reported at least three "blasts."

Around two percent of India's 1.4 billion people are Christian, according to the last census.

Jehovah's Witnesses are members of a United States-based Christian evangelical movement, who are best known for knocking on doors around the world, bible in hand, trying to convert people to their beliefs.

The movement, which preaches non-violence and is politically neutral, has a long history of being persecuted.

It is a millennial faith, meaning its members believe that the end of the world is near and that God's kingdom will soon rule over the earth.