Four people were killed and 24 injured in an explosion in one of Pakistan's oldest and most popular Sufi shrines in Lahore on Wednesday, police said.
The blast occurred near the entrance gate for female visitors to the 11th century Data Darbar shrine, one of the largest Sufi shrines in South Asia,police said.
PTV aired footage showing damaged vehicles and emergency personnel at the scene.
The shrine has been targeted previously, in a 2010 suicide attack that killed more than 40 people, and is guarded by heavy security.
Sufi worshippers, who follow a mystical strain of Islam, have frequently been the target of bloody attacks by Islamist militants, including the Islamic State group in Pakistan.
Militant Islamists see visits to Sufi shrines and some rituals at the graves of Muslim saints as unIslamic.
Police in the eastern city confirmed that a blast had taken place but did not immediately give a toll.
Local police official Muhammad Kashif said the blast may have been “a suicide attack targeting security officials' vehicle”.
“We are trying to get more details from the site,” he added.
Another police official, who spoke on condition of anonymity, said a security vehicle had been targeted in the blast.
Pakistan's push against extremism was stepped up after the country's deadliest ever attack, an assault on a school in Peshawar in 2014 that left more than 150 people dead — mostly children.
Since then, security has dramatically improved — but militants retain the ability to carry out dramatic attacks.
Major urban centres such as Lahore, Pakistan's second largest city and the provincial capital of its wealthiest province, Punjab, are not immune.
An attack in Lahore in March last year left nine people dead, while a major blast targeting Christians celebrating Easter in a park in 2016 killed more than 70 people.
Critics have long argued the military and government crackdown does not address the root causes of terrorism.
