At least eight people have been killed and 25 others injured in a powerful blast that targeted security forces guarding a famous Sufi shrine in the eastern Pakistani city of Lahore, police said.
High-ranking police official Arif Nawaz Khan told reporters that the May 8 explosion was a suicide attack that hit a vehicle carrying police officers.
The official said five officers were among those killed in the attack outside the shrine, known as Data Darbar, where Sufi saint Ali Hajveri is buried.
Police said hundreds of pilgrims were inside and outside the shrine when the explosion took place.
Security forces cordoned off the area.
Prime Minister Imran Khan condemned the bombing, which comes one day after the beginning of the Muslim holy month of Ramadan.
Khan said authorities had maintained a general security alert but that there had been no specific warning about a threat to the Data Darbar, one of the largest shrines in South Asia that attracts hundreds of thousands of visitors every year.
The Data Darbar has been targeted previously -- a 2010 suicide attack there killed more than 40 people -- and is guarded by heavy security.
Sufism is a form of Islamic mysticism that exists across the Islamic world. Sunni extremists view Sufism with hostility and have carried out attacks on Sufi celebrations and shrines.