About 100 people were wounded in the attacks in Lahore, which were timed to take place when the Moon Market was as its busiest just before 9:00 p.m. Authorities initially said both were believed to be remote-controlled blasts but later said a suicide bomber was suspected to have carried out at least one of them.
The blasts came within 30 seconds of each other, leaving dozens of cars and shops ablaze late into the night.
Many victims were women and children, including a dead 2-year-old, a police officer said.
Most of the militant attacks in recent weeks have been directed at security forces, though several have targeted crowded public spaces such as markets, apparently to cause public anger and increase pressure on the government to call a halt to the offensive. More than 400 people have been killed, including 105 in another market frequented by women in Peshawar in October while U.S. Secretary of State Hillary Clinton was visiting Pakistan.
The Taliban generally claim responsibility for those attacks killing security officers, but they do not acknowledge carrying out the attacks targeting civilians. Government officials and security analysts say there is little doubt the militants are behind all the attacks.
Moon Market sells female clothes, shoes and cosmetics and is especially popular with women and their children.
Lahore's top government official, Khusro Pervaiz, said there were at least 34 dead and 109 wounded.
"There was a blast. Then there was another," said Mohammad Nauman, who was bleeding from his nostrils. "Nobody knew what was happening. Everybody was running. There was fire everywhere."
Lahore is Pakistan's second-largest city and is not far from the border with India. It has been hit several times by militants over the past year, including an attack on the visiting Sri Lankan cricket team and several strikes against security installations.
The attacks came hours after a suicide bomber killed 10 outside a courthouse in Peshawar, a northwestern city that has been repeatedly hit by bombings since October. It lies on the main road into the border region, much of which is under the control of al-Qaida and the Taliban.