India's Federal Home Minister Sushilkumar Shinde said the bombs were attached to two bicycles about 150m (500 feet) apart, the Associated Press reports.
He said eight people died in one explosion and three in the other.
More top news
The 72-year-old had to be helicoptered from the mountain, when he was just a few hours from the summit on Monday.
Inspectors also found the electric meter had been bypassed to avoid paying for electricity.
James Ellington and Nigel Levine were training in Spain when they were involved in a head-on collision with a car.