The explosions occurred at a fruit market in Badami Bagh area of Lahore at 9.40 pm. Several of the injured were vendors, police and witnesses said.
According to witnesses and police officials, one explosive device was planted in a cart while another was hidden in a box of mangoes kept in a truck.
Several vendors were among the injured. They were taken to the Mayo Hospital, where officials said five of the injured were in a critical condition.
People fled the market in panic after the two bombs went off within five minutes of each other.
The state-run Rescue 1122 service and other civic agencies reached the spot and participated in the rescue operation.
"I was passing by the fruit market on my motorcycle when the explosion occurred and I fell to the ground. I recovered consciousness in hospital," Muhammad Saddiq told reporters at Mayo Hospital.
Rescue service spokesman Farooq Ahmed said five persons, including a boy, were in a critical condition and undergoing surgery.
Authorities declared an emergency in hospitals across Lahore.
Superintendent of Police Multan Khan said terrorists had struck despite security measures put in place at the market.
"It is not possible to physically check every vehicle coming into the market," he said.
One of the bombs was of low intensity while the other was powerful, he said.
Police have been put on high alert across Lahore following the attack, he said.