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
Sir Bruce Forsyth, Sir Cliff Richard and the Prime Minister have been among those paying tribute to Cilla Black following news of her death.
TV favourite Cilla Black, who has died aged 72, gave viewers a "lorra, lorra laughs" during her long career.
Some rain in the north. Very warm sunshine in the south