A roadside bomb killed the custodian of a Sufi Islamic shrine and two of his guards in northwest Pakistan on Monday, a security official said.
The bombing took place in Dera Ismail Khan district of Khyber Pakhtunkhwa province bordering the restive tribal region where Pakistan is carrying out a military operation against known terrorist groups.
"About 10 to 15 kilograms of explosives were used in the bomb planted under a small bridge on the outskirts of Dera Ismail Khan," Zainullah Khan, head of the bomb disposal squad, told ucanews.com.
Two passers-by were injured in the explosion, Khan said.
Faqir Jamshed, caretaker of Noori Shah Shrine where annual celebrations culminated few days ago, was killed in the attack.
No group has claimed responsibility for the attack, but suspicions are likely to fall on the Pakistani Taliban and allies who want to impose a strict version of Islam and Sharia laws and who are strictly opposed to Sufism, a mystical and tolerant form of Islam.
Sufi shrines have frequently been the targets of terrorist attacks in Pakistan in recent years.
In February, at least eight people were killed when Taliban gunmen on motorcycles fired on a shrine on the outskirts of Karachi.
In one of the bloodiest attacks in July 2010, twin suicide bombers attacked the Sufi shrine Data Durbar in Lahore, killing 50 people and wounding 200 others.