As many as 250 others were injured, according to Khadim Hussain Rind, the Hyderabad Police inspector general.
The Islamic State Khorasan, ISIS' affiliate in Afghanistan and Pakistan, claimed responsibility for the attack in a phone call to CNN.
The Amaq news agency, which is affiliated with ISIS, reported the attack was carried out by a suicide bomber in an explosives vest.
Thousands of worshipers, including families with their children, had gathered at the iconic shrine for the Sufi ritual of Dhamal, which involves music, chanting and prayer. The shrine is more than 800 years old.
Prime Minister Nawaz Sharif called the attack "brutal."
"I have directed all the state institutions to mobilize all resources for rescue and relief after this brutal terror attack on Lal Shahbaz Qalandar's shrine," the Prime Minister said in a statement.
Police and security officers cordon off the area of a deadly bombing, in Lahore, Pakistan, on Monday, February 13, 2017.
Police and security officers cordon off the area of a deadly bombing, in Lahore, Pakistan, on Monday, February 13, 2017.
The spokesman for the Pakistani military blamed operatives from Afghanistan for a recent spate of attacks on the country.
At least 60 killed in suicide attack at Pakistani shrine
