The bombs exploded minutes apart outside two churches situated in the majority Christian suburb of Yohana Abad in the eastern city, police said on Sunday.
The explosions, which police said seemed to have targeted both a Catholic and a Protestant church located very close to one another, occurred while Sunday services were going on.
Police said at least 14 people were killed and more than 50 people injured, and that the death toll could rise amid an ongoing rescue operation.
A witness said quick action by a security guard to stop one of the two suicide bombers from entering a church had prevented many more deaths.
The witness, Amir Masih, said the guard died along with the attacker after the latter blew himself up outside the church.
The attacks sparked street protests by hundreds of Christians in the district, with reports of two men being lynched on suspicion of involvement in the attack.
Prime Minister Nawaz Sharif condemned the attacks and said security was being stepped up.
The Taliban splinter group Jamaat-ul-Ahrar claimed responsibility for the blasts.
Islamist extremist groups and militants have often attacked Christians and other religious minorities over the past decade or more.
tj/ng (AP, Reuters)