A suicide bombing has struck the Muslim shrine of Data Darbar in the eastern Pakistani city of Lahore, killing dozens of people and wounding many more.
Data Darbar is one of the oldest Muslim shrines on the subcontinent.
It houses the remains of a Sufi saint, Abul Hassan Ali Hajvery. He is said to have lived on the site in the 11th Century.
He is one of the most well known and revered of the subcontinent's Muslim saints.
Reputed to have miraculous powers, he was an erudite scholar with several books to his credit.
Most are in publication today and have been translated into dozens of languages including English.
For centuries his tomb was visited by Muslims and Hindus in search of his blessings but since partition, most visitors have been Muslim, although people of all religions are welcome.
Pakistan's main opposition leader Nawaz Sharif is a frequent visitor.
The shrine is located near the Bha'tee Gate into Lahore's Walled City.
It was originally built by the Ghaznavi king Sultan Zakiruddin Ibrahim later in the 11th Century and has been expanded several times since.
There have been rising security fears in recent years after threats by Pakistan's Taliban militants.
The large size of the complex which houses the shrine and the fact that it is open at all hours to the public makes protecting it extremely difficult.