Five huts were damaged as the wall built "illegally" around the International Society for Krishna Consciousness (ISKCON) temple off Kanakapura road caved in, ACP (Law and Order) Kamal Pant told PTI.
Bodies of the victims were recovered from the debris, he said, adding heavy overnight rains might have triggered the wall collapse.
Karnataka Home Minister KJ George, legislator Krishnappa and Bangalore Mayor BS Sathyanarayana, rushed to the site and supervised the rescue and relief operations.
Speaking to reporters, Mr Sathyanarayana warned of strict action against ISKCON temple authorities for "illegally" putting up the wall adjacent to the slum. "It (wall) is illegal. We will take action," he said.
ISKCON spokesperson Bharatashrabha Das announced a relief of Rss. 5 lakh and Rs.s 50,000 to the kins of the dead and the injured.
He said the temple authorities were looking into the cause of the wall collapse. He alleged that some people living in the slum had used the adjacent ISKCON wall to build their houses.